The Pitts - Season 1 Episode 4 Dummy and Dummier
Overview: It's nearing time for Petey's birthday party, and he wants to go to Birthdays, Inc. to have more fun, convinced that any party Bob and Liz throw will suck. It does. Laser tag with flashlights, Dirt Bikes: The Board Game, and Liz won't let them watch a bootlegged copy of Spider-Man 2. When all the guests try to leave, Bob goes downstairs to the basement and retreives Morty, an old living, talking dummy who's holding a grudge against Bob for leaving him there in the basement for 30 years. Later he takes over the Pitts house and throws them out, and it's up to them (and a beaver) to get their home back.