Scooby-Doo on Zombie Island (1998)

Whatever doubts I had about the introduction of the actual supernatural to the universe of Scooby Doo were quickly obliterated when Fred yanked the head off of a zombie. Lots of clever little bits suggesting an uncommon amount of care, like the zombie hoard being a multi-generational band featuring pirates, confederate and union soldiers, and tropical shirt-clad tourists. Scooby and Shaggy take a big drink of water from the swamp after eating a hot pepper and are confronted by the zombies that live there. Shags and Scoob drank corpsewater.