The Worry Wart appeared in the Mopatop's Shop episode "Worries. He worries about everything, he was walking around in the shop under a wastepaper bin in case the sky should fall down on him. Also he could not wear a red hat because a bird might think he was a cherry and eat him up. His worrying started to affect the mouse family and they were worried about the wart not leaving. Mopatop manages to convince him that he should put on some glasses that made him see the bright side of things by telling him the glasses would prevent him from losing his eyelashes. After the Worry Wart saw the bright side of things through the glasses he was not worried anymore.
In "Worry and Fret," he comes into Mopatop's Shop to look for a gift for his wife.
In "The Great Strawberry Jam Sandwich Crisis," some Worry Warts target Puppyduck's strawberry jam sandwiches.