When you think about it, right from the very beginning of his first appearance, Captain America has been about transformation. Steve Rogers was a scrawny reject from the United States Army who instead volunteered to become the test subject for a Super Soldier Serum that literally transformed him from a weakling into a superhero.

RELATED: Superman’s Weirdest Transformations

With an origin like that, it is no surprise that writers have consistently re-visited the idea of transforming Captain America over the years, as you have a lot to work with via aging and de-aging the character and messing with the serum in his body. Of course, that does not explain all of Captain America's transformations over the years. Some of them are so offbeat that you never could have predicted them. Note that we're not getting into alternate timelines, like "What If...?" comics or "Marvel Zombies." That would be too easy. Now altered timelines? That's a whole other story. Here, then, are Captain America's strangest transformations (in chronological order).

15 OLD LADY CAP

Joe Simon and Jack Kirby managed to wait for an entire two issues of "Captain America Comics" before having Captain America and Bucky disguise themselves as an old woman and her foppish grandson. It was part of a plan to travel into the heart of Nazi-occupied Europe to rescue a powerful American businessman, who was about to pledge millions to the British war coffers before he was kidnapped by Nazi agents.

Watching Granny Cap walk around Paris and noting that they could have stuck around and fixed the problems in France, had they not been too busy on their mission, was a weird sight to see; as was seeing Cap lounge around in his hotel in his dress. In the end, it turned out that the Nazis had replaced the financier with a doppelganger, who was going to pledge support for the Axis. Luckily, Cap and Bucky travel to Berlin to save the financier. Bucky even gets a chance to kick Adolf Hitler and Herman Goerring's collective butt along the way.

14 RED SKULL CAP

For years, one of the biggest thorns in Captain America's side has been the Cosmic Cube, the reality-altering object created by A.I.M. that has frequently been stolen by the Red Skull and used against the world in general and Captain America in particular. In "Captain America" #115 (by Stan Lee, John Buscema and Sal Buscema), the Red Skull used the cosmic cube to mess with Cap by switching their bodies, so that the Avengers and Sharon Carter both believed that the Skull was Cap and that Cap was the Skull. Cap had to evade both his teammates and the police to keep himself free to stop the Skull's plans. Meanwhile, in Cap's body, the Skull severed the recent partnership Steve had formed with Rick Jones (who had become the new Bucky).

The Red Skull then sent Cap (still in Skull's body) to Exile Island, where the Skull's former allies, the Exiles, lived. He had betrayed them in their last adventure, so he thought it would be hilarious to see his former friends get their revenge on him while actually killing Captain America! Luckily, Cap used some clay to fashion a brand-new face for himself (yup) and ended up befriending another man on the island, Sam Wilson, to help him take down the Skull. Wilson became Cap's new partner, the Falcon, who helped get Cap back to his proper body.

13 WEAKLING CAP

"Captain America" #225 (by Steve Gerber, Sal Buscema, Mike Esposito and John Tartaglione) is perhaps best known for the strange origin that Gerber gave Captain America in the issue. As Nick Fury subjected him to intensive hypno-therapy, Cap recalled his real origins, which included his older brother, who died in the Japanese attack at Pearl Harbor. This is what drove Steve Rogers to enlist in the Army and then volunteer to become a test subject once he was rejected from the service (this was later explained to be a false set of memories, primarily because Cap debuted before Pearl Harbor). The trauma from the experience, however, left Cap somehow reverted to his weakling status.

Gerber was off the book with this issue, so incoming writer Roger McKenzie quickly abandoned the storyline in the following issue and had Cap return to his normal state by the end of "Captain America" #226. It also turned out that the Nick Fury in the story wasn't really Nick Fury, but all part of an overly-complex plot by the Red Skull against Captain America. The real Nick Fury had been transformed into the Red Skull in the hopes that Cap would kill the "Skull" while really killing his good friend, Nick.

12 OLD MAN CAP

John Marc DeMatteis' classic run on "Captain America" came to a close in "Captain America" #300, although in a much different manner than he initially intended. Originally, he was going to have Cap become a pacifist after the issue and continue writing the adventures of this new take on Cap. Rogers would have ultimately been assassinated due to his new views and replaced by the Native-American hero, Black Crow, who DeMatteis had recently introduced into the title.

Alas, we never found out, as DeMatteis was replaced on the title and his final storyline re-written, with the Red Skull successfully poisoning Captain America and making him age rapidly. The Skull then seemingly killed Cap's closest friends. This was all to make Cap so angry that he would kill the Skull, who was aging rapidly himself due to the effects of the suspended animation that kept the villain alive after World War II breaking down. The Skull wanted to be killed in battle by his oldest foe, but in the end, Cap wouldn't do it (that part of DeMatteis' story remained). The Skull then died in his arms. Cap, too, seemed ready to die, but then Black Crow showed up and cured Cap.

11 BARBARIAN CAP

In "Uncanny X-Men" #190-191, Chris Claremont, John Romita Jr. and Dan Green put together one of those small little company-wide crossovers that you would often see in 1980s Marvel Comics, where the interconnected nature of the Marvel Universe would be used to great effect (like the Fantastic Four staying in Avengers Mansion or Thor being involved in the "Mutant Massacre"). In the story, the old Conan villain,  Kulan Gath (who years earlier had accidentally transformed Mary Jane Watson into Red Sonja) transformed New York City with a powerful spell that threw everything in the city back to the era of Conan.

This included all of the superheroes within the city, including the Avengers. So, Captain America and the other Avengers were now, in effect, barbarian heroes without any memory of their past lives. However, whomever they were, personality-wise, before the spell, they remained. So, being that the Avengers were still heroes, Cap and his crew helped fight back and return things to normal. It was a lot of fun to see characters like Spider-Man and the Avengers given such a prominent focus in an "Uncanny X-Men" story.

10 TEENAGE CAP

In "Captain America" #355 (by Mark Gruenwald, Rich Buckler and Al Milgrom), Steve Rogers had only just begun to settle back into his life as Captain America (after getting the title back in "Captain America" #350) when he was contacted by his former girlfriend, Bernie Rosenthal, who was desperately trying to find her missing teenage sister. Cap discovered that there was a recent rash of teenagers going missing in the area, so he visited the Eternal known as Sersi (who would soon join the Avengers following this team-up) and had her use her powers to transform Captain America's body back to what it was like when he was a teenager for 48 hours. Her practically-magical powers did so, but that meant that he no longer had the Super Soldier Serum in his body!

After hanging around New York City, pretending to be a runaway, the undercover teenage Cap was soon kidnapped and taken into a camp designed to turn teenagers into killers. Among the "counselors" was the Red Skull's own teenage daughter! Luckily for Cap, what Sersi didn't tell him was that her spell would revert after 48 hours or after the 50th body blow that Cap received, whichever came first (the 50th body blow came first, of course).

9 LADY CAP

In a six-issue storyline from "Captain America" #387-392 (by Mark Gruenwald, Rik Levins and Danny Bulanadi), Captain America's girlfriend, Diamondback, and her friends, Black Mamba and Asp, were taken aboard what appeared to be a cruise for female super villains. As it turned out, it was all part of a plan by the villain Superia to essentially sterilize every woman on Earth except the women on her ship, which would both cause stronger future women due to the super-powered breeding, and also allow them to hold the world hostage.

Captain America and Paladin tried to rescue Diamondback, but ended up captured and put into a device that would transform them into women! Luckily for them, Black Mamba and Asp saved them before the process fully kicked in. Still, Cap and Paladin had to go undercover among the female villains as just two new female supervillains... with "underdeveloped chests."

8 CAP-WOLF

Captain America's pilot, John Jameson, had disappeared and Captain America went to go find him in this six-part storyline from "Captain America" #402-407 (by Mark Gruenwald, Rik Levins, Danny Bulanadi and some other fill-in inkers). Enlisting the help of his former Avenger teammate, Doctor Druid, Cap soon ran afoul of a town that seemed to be made up entirely of werewolves! Feral characters from around the Marvel Universe were also being drawn to this town, including Wolverine! Also ,Feral of X-Force showed up, which drew Cable in, as well.

The villainous Nightshade had teamed up with Desmond the Druid to draw in Jameson, who had the Moonstone. Desmond planned to merge with the moonstone to become the ultra-powereful Star-Wolf! First, Nightshade used a mesmerized Wolverine to capture Cap and then use a special serum she was working on to transform Captain America into a werewolf, as well! Cap soon took control of his "pack" and led them in a rebellion against Nightshade and Druid. With the assistance of Cable (who, again, was there to find Feral), they were able to save the day and Cap was turned back into a human.

7 ROBO CAP

In the year-long storyline, "Fighting Chance," (by Mark Gruenwald, Dave Hoover and Danny Bulanadi), Captain America discovered that the Super Soldier Serum powering his body was never intended to last forever. It was always meant to eventually break down, but as it turns out, in breaking down, it would also end up killing Captain America! So, Cap decided to devote his last months to finding and training new heroes to take over for him when he died. This story arc introduced two young heroes, Jack Flagg and Free Spirit.

As time went by, Cap's body began to turn on itself, so he had to eventually turn to his friend, Tony Stark, to build him a special armor so that he could keep up the good fight for as long as he could. Things took a dark turn after "Fighting Chance" ended, though, when Superia managed to find a cure for Captain America's affliction, but the Red Skull (who was also dying because he was then-currently in a cloned Captain America body, so the same degeneration was happening to him) took it for himself. In the end, Skull decided to share the cure because he needed Cap's help on a mission.

6 HEROES REBORN CAP

After being cured by the Red Skull, Captain America had a number of other adventures before he, along with most of the other heroes of New York City (except for Spider-Man, who literally got lost on his way to Central Park for the final battle) sacrificed their lives to stop the evil power of Onslaught, the nearly all-powerful psionic being. They essentially trapped the psionic energy of Onslaught by using their physical bodies to soak up his energy (it had to specifically be non-mutants, as mutant bodies would just enhance Onslaught's power). Once they anchored Onslaught with their bodies, the remaining X-Men destroyed what was left, killing the heroes and Onslaught.

As it turned out, Franklin Richards (the powerful mutant son of Mister Fantastic and Invisible Woman who had been kidnapped by Onslaught to amplify his powers) used his reality-warping powers to create a second Earth and re-created all of the dead heroes into new bodies based on how he remembered them (which is how the Wasp went back to a human body after being horribly mutated, and how Iron Man became an adult again after being replaced by a teenage version of himself). So, Captain America was also put into a new body for his new series, drawn by star artist Rob Liefeld. Eventually, the heroes returned to their Earth.

5 MEDIEVAL CAP

Once the heroes all returned to Earth, they began to reform the Avengers in "Avengers" #1-3 (by Kurt Busiek, George Perez and Al Vey), but before they could formalize things, they were caught up in a plot by the evil Morgan Le Fey. A variety of powerful mythological objects were up in the air, so all of the available Avengers assembled to collect them. Instead, Le Fey got her hands on both the Twilight Sword and the Norn Stones and used them, along with the Scarlet Witch's reality-altering powers, to power her Celtic magic to alter Earth into a new medieval era based on Le Fey's life in the time of King Arthur.

The Avengers were transformed into Le Fey's personal guard, with Captain America now called Yeoman America. However, the Scarlet Witch (kept captive by Le Fey) kept trying to get her teammates to break free of the spell and eventually managed to release Cap, as his spirit was so strong that he was able to remember who he was. He then recruited other Avengers whose sense of being an Avenger were especially strong (Hawkeye, Wasp, Monica Rambeau and Quasar) and they eventually helped Scarlet Witch turn the tide (along with a resurrected Wonder Man).

4 HOUSE OF M CAP

The Scarlet Witch was at the center of yet another time that Captain America (and the world) was altered by her reality-shaping powers. Following the events of "Avengers Disassembled," the Scarlet Witch snapped due to her trauma over losing her children (who were just creations of her own powers) and turned on her own teammates, killing a few of them. Her alleged father, Magneto, showed up and brought her to Genosha to take care of her. The Avengers and the X-Men then got together to debate how to handle the Scarlet Witch situation. Some even suggested that she was too powerful to let live. This sent Scarlet Witch's brother, Quicksilver, to her side, where he convinced her to alter reality so that mutants were the ruling class.

In this altered reality (as presented in "Captain America"#8 by Ed Brubaker, Lee Weeks and Jesse Delperdang), Captain America was now suddenly an old man, having never entered suspended animation during World War II. Instead, he lived to see the war finish, but also long enough to be ostracized by his willingness to stand up to Senator McCarthy on his anti-mutant hearings. Rogers also was an astronaut. He also spoke out against Magneto when he rose to power. In the end, he was just a lonely old man in a world ruled by a tyrant, which is not how he thought things would work out when he took down a different tyrant back in 1945.

3 SPIDER-CAP

The main villains of the "Spider-Man" crossover, "Spider Island," were the Jackal and the Queen. The Queen was a mutant who was experimented on by the United States government to try to find a successor to Captain America. She and Cap grew quite close to each other during this time. However, after he was seemingly killed at the end of the war, the government pretty much forgot about her. She escaped custody, though, and went into hiding.

Her powers could alter anyone with the "spider gene," and she teamed up with the Jackal to alter the genetics of the people of Manhattan Island in New York City (hence "Spider Island") and slowly give them first Spider-Man's powers, before then mutating them into giant spiders loyal to the Queen. However, her old love, Captain America, got special treatment and in "Amazing Spider-Man" #666 (by Dan Slott, Humberto Ramos and Stefano Caselli), he was transformed into a giant spider creature that was forced to obey the Queen's commands.

2 SERUM-LESS CAP

Ran Shen was one of the very best agents in the early days of S.H.I.E.L.D., competing with Nick Fury for those honors. However, after a mission against the Soviets and their Winter Soldier went horribly wrong, Shen's faith was lost in S.H.I.E.L.D. Meanwhile, a female scientist who Shen had fallen in love with lost her faith in her evil cause and the Winter Soldier lost his in his Soviet masters. Shen was going to work out a deal where all three of them could get out of their lives, but then Fury showed up and fulfilled the mission (kill or capture the scientist). Once his new love was tragically killed, Shen fully broke away from S.H.I.E.L.D. Fury's attack also sent Winter Soldier back to the Soviets, who were able to re-program him and keep him from escaping.

Shen merged with an alien dragon (one of Fin Fang Foom's people) to become the Iron Nail. He had tentacles that could drain both the effects of the Super Soldier Serum and Nick Fury's Infinity Formula. The Iron Nail began a plan to take down S.H.I.E.L.D. and though Captain America stopped him, in the process he had the Super Soldier Serum sucked out of him, leaving him just a really fit 90-something-year old man. Serum-less Cap was still a hero, of course, and continued to serve with the Avengers. He just let his friend, Sam Wilson, take over as Captain America.

1 HYDRA CAP

During a battle against a group of supervillains led by the Red Skull, who had been altered by a S.H.I.E.L.D.-controlled Cosmic Cube to keep them out of the way of the rest of the world, Steve Rogers was returned to his fully-powered self. He returned to the name Captain America, although he insisted that Sam Wilson continue his good work as Cap, even insisting that Sam keep using the famous shield, with Steve getting a new one. Things seemed back to normal... but appearances can be deceiving.

What few people knew was that the now-sentient Cosmic Cube had bonded with Red Skull and she wanted to do whatever she could to please him, looking up to the Skull as a father figure. So, when she transformed Captain America back to his youthful self, she also altered reality so that Captain America was now a life-long follower of the same beliefs as the Red Skull, and a fully-fledge member of HYDRA! That was how the Cube believed things were supposed to be! So, Cap was now a secret agent of Hydra, and has been for his whole life. This series, at the time of this list's writing, is still ongoing, but it's definitely one of the most controversial moments in the long history of the character.

What's your favorite Captain America transformation? Let us know in the comments section!