Stitch, also known as Experiment 626, is the titular protagonist of the Lilo & Stitch franchise.
He was in Disney in Shadow and Shell Game, and was mentioned in Power Play. They described Stitch as an alien with a genetic malfunction that dressed up like Elvis and was a cross between a koala bear and a cuddly dog. Stitch was helping the pirates from the Pirates of the Carribean ride catch Finn and Maybeck. Stitch only said one thing and that was,"You don't belong here!". He chased Finn and Maybeck into alligator-infested waters at Tom Saywer Island. Amanda and Finn came to the conclusion in the fourth book that Stitch had a spell casted on him, which was casted by the Evil Queen. He also appeared in the fifth book saving butts from the rescue dummies at Typhoon Lagoon. He holds off the dummies and helps Finn escape. It is mentioned that he most likely has a grudge against the dummies and vice versa. He bites off one of the dummy's arms and most likely destroyed the others or scared them away due to their silence.