The Unbeatable Squirrel Girl has earned her name through and through, fending off Dr. Doom, MODOK, Terrax, Thanos, and other titans of Marvel infamy. But how do her squirrel-based powers make her so formidable? That's the big question, which is why so many Squirrel Girl fan theories try to explain the source and/or parameters of her surprisingly indomitable powers.
Of course, many fan theories about Marvel's Squirrel Girl focus specifically on her defeat of Thanos in a 2005 Great Lakes Avengers holiday one-shot, probably her most famous moment. Now that Thanos has finally made his presence felt in the MCU, the Marvel fan base is left wondering if Squirrel Girl may be the one to take him down.
In case you're not familiar with The One Above All, Redditor /u/throwaway12junk explains, "The One Above All (not the Celestial) is the supreme god of the multiverse. Known as The Source in DC, it is creator of all things that exist including but not limited to Living Tribunal, Eternity, Infinity, Oblivion, and Death."
/u/throwaway12junk believes this entity is responsible for Squirrel Girl's apparently unrivaled power. This Redditor muses that she couldn't have gained such power from an artifact like the Cosmic Cube because nothing like that is ever indicated in the comics, so:
At this point the next logical step is being blessed or aided by a powerful being such as Galactus, a Celestial, or one of the cosmic entities. None of these being[s] would care, better yet aid, Squirrel Girl in any way, shape or form, so then you have to move up another step.
The only things left are Living Tribunal, and One Above All. The former is immediately disqualified as its sole purpose is to maintain balance in the multiverse. Aiding Squirrel Girl against Thanos would bring only imbalance because, well, there are other more powerful beings who can challenge and defeat him. So the only thing left is One Above All.
Evidence to support this claim is mostly from the fact it has appeared personally to a few other Marvel Heroes. Including Benjamin Grimm, and Peter Parker.
Now why would One Above All aid Squirrel Girl? Because why the hell not? It can do whatever It damn well pleases, to the point where consequences only exist if It declares they exist. Squirrel Girl could have been a random pick or specifically created by It to be an agent for no reason at all.
Redditor /u/BiagioLargo's theory is brilliant in its simplicity, as it ponders the possibility that Squirrel Girl is truly an accidental hero:
I know Squirrel Girl can defeat anyone in a fight. That's her real superpower. So in order to beat her you have to kill her without her even knowing you're there. Sniper, c4, etc. However it occurred to me she might also have Magoo/Mindy powers like if someone tried to snipe her she'd be ducking to pick up a penny right as they pulled the trigger oblivious to the dangers. So whether or not she has that power determines a lot of things.
If you love semantics then you're really going to love Redditor /u/seancurry1's theory about Squirrel Girl's unbeatable nature as a result of her ability to set rules for her reality:
Personally, I define Squirrel Girl's power as the inability to lose any fight after she's set her own terms for victory... in a universe as immense, multi-tiered, and layered as ours, I think it's perfectly within the bounds of reason to suspect that there is a larger force, being, or power out there that has, for whatever reason, taken a liking to her and made it impossible for her to lose... Once Squirrel Girl defines her personal victory conditions, she cannot lose.
So, with that said, her power seems to derive more from semantics and logic than actual physical ability (though she is a formidable combatant in her own right). With that knowledge, I believe any number of players could devise a logic trap that she cannot win. There's a detective/sorcerer from another multiverse, John Constantine, that achieved a similar feat by selling his soul to two demonic parties so they both fought to keep him alive.
I could see a similar scenario play out with Squirrel Girl, provided her opponent was aware of the root of her powers. A scenario where her victory conditions cause enough harm that she cannot morally attempt to achieve them, so she only wins by losing. The logical paradox would break the hold of whatever entity or power that favors her.
Reddtior /u/GenocideSolution seems to be disturbed by their own theory that Squirrel Girl could potentially bring about a world overrun with super-powered squirrels:
Either squirrels themselves are intelligent enough to be capable of conversing with Squirrel Girl (in which case that raises hundreds of ethical pest control concerns) or she is capable of granting intelligence to squirrels.
If the latter, where does her range end? It appears that every squirrel she communicates with is capable of communicating with any squirrel it comes into contact with. They can carry out plans, even plan themselves. There is an estimated 21 billion squirrels in the world. This makes her capable of coordinating the single largest sapient force known to any Earth based organization. Larger than most space organizations as well, since they prefer quality over quantity.
If superpowers are not limited to humans alone (and they aren't, as shown by all the other superpowered nonhuman beings in Marvel), that means there are probably superpowered squirrels as well.
So yeah. Squirrel girl is f*cking scary.