Tom Hiddleston's Loki has become by far the most popular villain in the Marvel Cinematic Universe. Rivaled only by Thanos, fans genuinely find Loki appealing, even when he's on the other side. It's to the point where the arc of the character sometimes makes him an anti-hero. He's even getting a Disney+ series.
Loki in the comics has been portrayed very differently over the years. The character's popularity from the films and the remarkable portrayal by Tom Hiddleston have changed the portrayal of the character in the comics. When exploring the differences, it's important to not include areas where the films influenced the comics.
10 Not Accurate: Commands the Chitauri
In the first Avengers film. Loki was the primary villain, but he commanded an army from an alien benefactor. The aliens referred to as the Chitauri, are essentially a mindless army bent on destruction. The thing is that the Chitauri weren't originally an army waiting to be commanded.
In Ultimates, the Chitauri are the aliens out to purge the Earth, eventually getting on the bad side of Captain America and SHIELD. They're led by one of their own, who's referred to by an alias he's used going back to World War II, Herr Kleiser. The Chitauri in that series is very similar to the Skrulls, changing their shape to infiltrate SHIELD.
9 Accurate: Turned Thor Into a Frog
Loki once played a trick on Thor where he turned the Thunder God into a frog in Central Park. Creator Walt Simonson crafted the four-issue story that had Thor get involved with the Central Park war between the frogs and the rats. Many fans consider it surprisingly good.
To transform Thor, he uses his cosmic transmitter to enchant a random woman. When she kissed Thor, it turned Thor into a frog and erased the woman's memory. This also kept Thor out of the way while Loki attempted to seize the empty throne of Asgard.
8 Not Accurate: Brotherly Love with Thor
While Loki has allied himself with his foster brother in the comics, almost always, he is the antagonist. The first Thor film establishes that their relationship growing up is very close, although Loki does feel overshadowed. Upon learning his true parentage, these feelings lead him to betray his adopted brother.
There's never any clue that the two were close in childhood. Almost from the beginning Loki's role as the god of mischief put him at odds with his foster brother. There's never any clue that they were close enough to come up with something as hilarious as "get help."
7 Accurate: Son of Frost Giants
It's part of the motivation for Loki's betrayal that he's not of Asgard. He was taken by Odin after he was left to die by the Frost Giants. It's a nature that gets small references in subsequent films, but it is a minor aspect that gets overshadowed by Thor embracing him as a brother.
In the comics, the canon is that Loki was adopted at a young age. While Thor, Odin, and Frigga treated him as family, the others in Asgard, treated him very differently. This sparked his development as the God of Mischief.
6 Not Accurate: Female Loki from the Comics
Upon the rebirth of the Asgardians following Ragnarok, Loki was reborn as a woman. The MCU has yet to address this but hope springs for it to be included in the Disney+ series.
In the comics, female Loki lasted for some time, making the inclusion through Norman Osborn's takeover of the superhuman forces of the United States. Unfortunately, she met her end in battle with the Void after Osborn turned Loki's schemes into the destruction of Asgard.
5 Accurate: Masqueraded In Different Guises
A trick Loki uses his sorcery for in the films, especially in Thor: The Dark World, which even ends with Loki taking the identity of Odin. In that role, he assumes the throne of Asgard. In walking with Thor, he assumes the form of Captain America, making for a clever Chris Evans cameo.
In the comics, the best use of this was during the Acts of Vengeance event that saw Marvel's villainous masterminds being brought together by a mysterious man with black hair in a suit. That benefactor is Loki, scheming to destroy the Avengers. The female Loki would later masquerade as the Scarlet Witch. There's precedent for this in the comics.
4 Not Accurate: Masqueraded as Odin
In the film's Loki masqueraded as Odin to surreptitiously seize the throne of Asgard. It was a clever reveal after it looked as if he were killed. It also left questions that would later be answered in Thor: Ragnarok.
Simply put, this never happens in the comics. Odin is extremely powerful, and it seems that Loki has learned not to earn his wrath. Masquerading as the All-Father could probably find the God of Mischief once again chained to rock like he was for murdering Balder.
3 Accurate: Responsible for Bringing the Avengers Together
It wasn't so much the Chitauri invasion of New York that drew the Avengers together, it was Loki's murder of Phil Coulson. While it has never been revealed if any of the Avengers learned of Phil's resurrection, Loki did plenty of things to bring these six heroes together.
In the comics, the story is legendary. In a scheme against Thor, Loki tricks the Hulk. He warps a radio signal to go to Don Blake, and in turn, that distress call is also answered by Iron Man, Ant-Man, and the Wasp. It's such an iconic start that it almost had to be used for the MCU.
2 Not Accurate: Extremely Close To Frigga
Being raised by Odin means that Loki was also raised by Frigga. At least in the MCU, it does. In the films, we see that Frigga and Loki have an especially close mother and son bond. This stems partly from Loki's early affinity for magic.
In the comics, Loki doesn't have a particularly close relationship with his adopted mother until after the films began to affect the comics. Loki was used by Frigga as a spy against Malekith. Hed used this position to thwart Frigga's murder by attempting to kill her himself.
1 Accurate: Uses Sorcery
In the Marvel Cinematic Universe, Loki wields powerful sorcery, often used to create illusions. He was trained by his foster mother who herself wielded powerful Asgardian magic. Initially, in the comics, Loki's mystical abilities were downplayed before coming more to the fore as the structure of Asgard was expanded upon.
In the comics, this led Loki to exhibit abilities like teleportation and animating inanimate objects. He's enhanced the powers of humans, especially criminals. He's even proven to be immune to mind control or attack. Loki's abilities even have enabled him to survive being beheaded, showing that in the comics, Loki's sorcery might even be more powerful.