Question Mark is a short man (the same height as Batduck) with black hair, who wears a green leotard with purple gloves, boots, and a mask. He also has a large "?" that is around his neck.
Question Mark was first seen when Batduck said his name and the names of the other villains in a frightened tone. After defeating The Puffin , Question Mark asked him a hard riddle, "How can you tell if an Elephant's been in your bed?" but Batduck tricked him by asking what kind of Elephant; African or Indian, in which Question Mark repiled, "Gee, I don't know." and Batduck defeated him with an extendable boxing glove. Later, he and the other villains were crushed by the Giant Baby doll and arrested afterwards.
- Question Mark is a parody of The Riddler, one of the antagonists of the Batman series
- He is one of two Batduck villains who is human, the second is Polecat Woman.