Meet the Reaper / Skeletons In the Water Closet / Opposite Day

S1 E1: "Meet the Reaper" Billy and Mandy, two neighbor kids, play a game with the Grim Reaper for the soul of a sick hamster. "Skeletons In the Water Closet" Billy's overprotective mom discovers the Grim Reaper sleeping in her son's room. "Opposite Day" Grim's patience and sanity are put to the test as he is forced to deal with an unconventional holiday where everything means the reverse of what it normally does.