Reptil joins the Super Hero Squad and Wolverine is assigned to be his mentor. He immediately gets to prove his worth as the Squad races to stop Doom and the Wrecking Crew obtaining a hidden fractal.

During a chaotic battle with Klaw and Screaming Mimi, a fractal's cosmic power turns the Hulk into the Gray Hulk. While Falcon and the Wasp babysit this unlikable, brainy Hulk, the Squad chase down the Lethal Legion in a battle to save Super Hero City.