31 Days of Halloween Nostalgia:
Day 9 | The Grim Adventures of Billy & Mandy | Billy & Mandy’s Jacked-Up Halloween (2003)
On Halloween night, Billy goes Trick-or-Treating as Grim, complete with magic scythe. Jack, made headless by Grim in a past lifetime, takes advantage of Billy and harnesses the power for himself. Technically the whole series is rather Halloween-y, but this is definitely an interesting spin on the headless horseman of sorts.