Placulus is the main antagonist of the children's special Dr. Rabbit and the Tooth Defenders. He is the leader of the plaque monsters who intends to get rid of the Tooth Defenders and take over Tooth City inside the mouth of a boy named Billy.

When finally, the dog member of the team tells Billy to stop snacking (on gumdrops and soda) for a while, it upsets Placulus who still intends to take over; however, the girl member with the brush brushes him. He plans to continue to take over, only vanishing away.