The Grim Adventures of Billy & Mandy

Aren't You Chupacabra to See Me? (4x16)

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After being utterly bored of watching the same movie 60 times in a row, Grim takes Billy and Mandy to "Underworld Video" where they rent "The Legend of Chupacabra". While Billy watches the tape, a small, pink chupacabra emerges from his television and Billy decides to keep it as a pet, naming it Daisy. In the end, Mandy and Grim convince Billy that he is inept in taking good care of pets, and they return the blood-sucking chupacabra to the videotape.