When Angelica is told she is too big to play in the new playhouse Chas has built for the other Rugrats, she tells them that Chuckie is actually an alien and that the playhouse is a space ship. - Description from Klasky Csupo
Angelica is having the babies be her slaves and bring her things. Suddenly, Chas brings a new playhouse he built for Chuckie and his friends. The babies are excited to play in it. When Chas leaves to answer a phone call, Angelica pushes the babies out of the way. She tries to go in but she can't fit. She complains that it's too small. Phil says that he and the others can fit in, but Angelica says "no". She says if she can't go in there, none of them can. Tommy complains that isn't fair. Chas comes and gets Chuckie so he can say hi to his grandma on the phone. Angelica says that they can't go in the playhouse because Chuckie is an alien. She says she found out one night. Chuckie comes and asks if they are going to play in the playhouse. Chas's new playhouse for his son and friends to play with proves to be the perfect "cover story". In an effort to alienate the Finster child from his friends, Angelica tells them that he is an alien from Outer Space, who plans to "capture" all Earthlings.
The appearance of the "Aliens" is very similar to the reptiles of the episode "Calling All Creeps" of the live action series "Goosebumps".