Puddle Jumping The Grim Adventures of Billy & Mandy : Season 4 Episode 18

When Billy jumps into a supernatural puddle (a Cosmic Sinkhole, according to Grim), it takes him to the home of Granny Applecheeks, who wants to bake him into a pie. It is up to Mandy and Grim to save him if the puddle can take them to the right place.