D-Men are goblin-like creatures that work for Muffy that reside in The Underwhere in The Flip Flop Show. There are two types of D-Men. First, there are D-Men that work directly with Muffy, who wear suits and are flooded with work. The second type of D-Men wear loincloths and are mostly seen in the Underwhere Road and make sure people safely climb upward to The Overthere. The D-Man's name is a pun on "demon" or "devil" and the slang term "G-Man," which means "Government Man." "Government" refers to the United States Federal Government, and the term itself is a slang word for a Federal Bureau of Investigation (FBI) agent. Similarly, D-Men are agents of Muffy, ruler of the Underwhere.
Official art of D-Men.