Here are some of Squirrel Girls feats.
Supposedly defeated Thanos and attracted the the attention of the Watcher.
Defeated Dr. Doom
Convinced Galactus not to destroy the planet and befriended him.
Was Ironman's sidekick.
Breaks the fourth wall better than Deadpool.
Here's just some intense shit about her and she became a zombie, that's pretty terrifying!
She has been compared to Superboy Prime and even Spawn!