The green-skinned, child-like version of the Hulk is the most commonly known, but readers know that there are many more versions, ranging in color, temperament, power, and personality. For example, the grey version went by the alias Joe Fixit and spent some time as a mob enforcer in Vegas, whereas the red version was actually long-time Hulk adversary General Thaddeus “Thunderbolt” Ross. Both versions were mean and dirty fighters, tactically capable and downright nasty. Which was the worst? Here are The 5 Worst Things The Grey Hulk has Ever Done (& the 5 Worst That The Red Hulk Did).

RELATED: Red Hulk: 10 Things He Can Do That Regular Hulk Can't

10 GREY HULK: ARM-BREAKER

Acts of Vengeance was a late ‘80s - early ‘90s crossover that saw the Marvel villains unite to swap arch-nemesis in the hopes that facing unfamiliar foes would finally defeat the heroes. To that end, Doctor Doom recruited the Grey Gargoyle, a villain with the ability to turn anything he touches to stone, to immobilize the Hulk. A self-styled ‘artist’ who sells transfigured humans as sculptures, the Gargoyle managed to immobilize Bruce Banner, until his night-induced transformation turned him into the Hulk. Once the Hulk’s enhanced healing factor kicked in, he defeated the Gargoyle by breaking his arm. Arguably not a severe punishment by comic book standards, until you factor in the Gargoyle's reliance on his touch to further his ‘art,’ to say nothing of needing to touch himself to revert to human form!

9 RED HULK: DOWNED HELI-CARRIER

A bulk of the Red Hulk’s most heinous deeds came within the first few years of Jeph Loeb and Ed McGuiness’ run with the character. Following his assassination of the Abomination, the Rulk got into an altercation with Iron Man. In his capacity as Director of Shield, Tony Stark was hot on the trail of Rulk, and their ensuing altercation downed the S.H.I.E.L.D. heli-carrier into a field in New Jersey. Although there were no casualties, the entire field was irradiated by gamma rays, to say nothing of the destruction of one of S.H.I.E.L.D.s' most important pieces of equipment.

RELATED: 10 Things You Didn't Know About S.H.I.E.L.D.

8 GREY HULK: TOXIC WASTER

The Grey Hulk was smaller and less powerful than his more famous green incarnation, but what he lacked in size and strength he made up for in cunning and pure meanness. The Abomination found this out the hard way when he battled the Grey Hulk in the first part of the Countdown storyline. Forcing Banner to change to the Hulk so as to continue their rivalry, the Abomination made one cardinal mistake: he unfavorably compared the Grey Hulk to the green one, a sore spot for “Joe Fixit.” Here, the Grey Hulk exercised his guile and nastiness and dumped the Abomination into a few vats of toxic waste, horribly scarring him and ending their fight quickly.

7 RED HULK: STONE COLD KILLER

When the Red Hulk first appeared, he did so with a pretty big feat: by killing the long-time Hulk foe The Abomination. Told in flashbacks by Doc Samson (who was recreating the scene of the crime through a forensic narrative), the sordid ordeal revealed not just a world-class beat-down, but a cold-blooded murder, as The Abomination was shot with a high-powered energy weapon multiple times. This immediately established the new Hulk as a deadly force not to be trifled with, as he had killed a classic villain with no qualms and in a ruthless way.

RELATED: Abomination: The 10 Weirdest Facts About The Hulk’s Strongest Villain

6 GREY HULK: NO BIG THING...

One of the classic rivalries of the Marvel Universe has been the Hulk vs the Thing, and it was only a matter of time before they met again when the Hulk switched his color palette. Through the machinations of Doctor Doom, the Hulk had his chance at a rematch, although against an over-powered Thing. Facing a sound defeat, the Hulk changed his tactics mid-battle, luring the Thing underwater where he nearly drowned him. Unscrupulous tactics aside, the Hulk’s willingness to partner with Marvel’s premiere villain, as well as nearly killing one of its beloved heroes, cements this as one of the worst things he’s ever done.

RELATED: 10 Things Fans Forget About Doctor Doom

5 RED HULK: BRUTAL MURDERER

During the Fall of the Hulks storyline, The Intelligencia is on a quest to kidnap the Marvel Universe's smartest people to (presumably) attempt to widen their already considerable influence on world affairs. In attempting to thwart their plans, the Rulk comes into direct conflict with the Red Ghost and his super-apes, and a battle ensues. To prove to the Red Ghost that he means business, the Rulk savagely rips apart one of the Ghost's super apes' heads by the jaw! Needless to say, this was a completely brutal and visceral display of power, but more disturbing was the Rulk's willingness to use unnecessary force to prove the extent of his violent domination.

4 GREY HULK: NO HESITATION

Although he had a good run in the late '80s and early '90s, the Grey Hulk has made sparse appearances since his personas were first merged into the Professor, and later swapped out for his savage or and child-like incarnations. However, the "Joe Fixit" persona that was associated with the Grey Hulk has since made a resurgence in the currently running Immortal Hulk series and seems more ominous and willing to take a life than in his previous incarnation. In fact, in one of the most recent issues, he kills General Fortean in the Below-Place with no hesitation, something he has historically had qualms about.

RELATED: 10 Things We Still Can’t Believe Happened In The Immortal Hulk

3 RED HULK: EARTH SHAKER

03. RED HULK - EARTH SHAKER - Red Hulk vs Thor

Following his destruction of the Heli-Carrier, the Rulk got into a massive confrontation with his green-skinned counterpart in the deserts of Nevada, which culminated on the Golden Gate Bridge in San Francisco. Sidelined for awhile due to the Red Hulk’s superior battle tactics, the Green Hulk lay incapacitated while Thor dealt with the Rulk. The battles between the Rulk and his adversaries caused the fault lines underneath the city to move, leading to a massive earthquake. Luckily, the Avengers were on hand to deal with the situation, but triggering an earthquake in a highly-populated area is one of the worst things the Red Hulk has ever done.

2 GREY HULK: WORST EX-BOYFRIEND EVER...

In establishing his life in Las Vegas, the Hulk began a relationship with Marlo Chandler, a rather tall and buxom fitness instructor (and future Mrs. Rick Jones). However, once Marlo witnessed the realities of “Joe Fixit’s” life as a mob enforcer, she broke off the relationship. During one last meeting to clear the air between them, Marlo was attacked by Jack Russell (aka Werewolf by Night).

For a brief moment, before he stopped him from killing her, the Hulk actually considered allowing Marlo to be killed by the werewolf, in retribution for her ending the relationship. This was a new low for the Hulk, and one he gladly came to his senses from.

1 RED HULK: CALLING IN THE WORLD-EATER

Comics 01. RED HULK - CALLING IN THE WORLD EATER - Red Hulk Rides Silver Surfer's Board

As part of a game by Elders of the Universe, the Grandmaster and the Collector, the Red and Green Hulks (along with the team members of their choice) were plucked from various points in time and forced to fight in a cosmic wager. Although the Green Hulk chose his former partners in The Defenders, the Red Hulk managed to kill the Green Hulk, get the drop on the Silver Surfer, absorb his cosmic energy and steal his board, and actually confront Galactus! Although Galactus was easily able to subdue the Rulk, he vowed to take revenge on the planet that produced him, meaning that (due to time displacement) his first visit to Earth was due to the Red Hulk's actions!

NEXT: Doomsday Vs The Hulk: Who Would Really Win In a Fight?