The Grim Adventures of Billy & Mandy

Home of the Ancients (4x24)

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When Grim misuses his powers to play bowling with asteroids, he is taken to the Underworld court and sentenced to 50 hours of community service. Then, at a retirement home, Billy, Mandy and Grim go to the supernatural wing, which is the Home of the Ancients, a place for retired, geriatric monsters. There, Grim meets his childhood idols, the Bride of Frankenstein, Dracula and the Wolf Man. Despite Billy's comments that the old monsters are finished, Grim sets out to prove that they are still scary. In the end, Grim tries to scare a bunch of kids in the woods, but the old monsters ruin his attempt and he walks out on them. (Grim is later put on trial for abandoning kids and the elderly out in the woods, who pleads that there is a possibility they may not have been "eaten alive by bears")