Swamp demons come from the imaginations of the villainous farmers in The Muppet Musicians of Bremen. When the traveling musician animals mistake the farmers for a family, the superstitious and cowardly farmers mistake the musicians for swamp demons.

Image Swamp demon Character As viewed by
Leroy swamp Tree Troll Leroy Mordecai Sledge
Rooster swamp Bush Bat T.R. Lardpork
Catgut swamp Mud Monster Catgut Caleb Siles
Rover joe swamp Slime Serpent Rover Joe Mean Floyd