The Little Green Aliens were all secretly taken home by one of the toddlers, setting up a course of events that ultimately leads to one of the saddest endings in film history. It was so sad, in fact, that Toy Story 4 had to be created in order to render the previous film non-canon and somewhat alleviate the widespread PTSD in all the kids who had to watch that traumatic scene.
Bill & Ted's Excellent Adventure