Mr. Wolf is a man with an ability to turn into a werewolf. He appears in the comic book series Teen Titans Go!.
In "What Time is it, Mr. Wolf?", Mr. Wolf requested the help of the Titans to watch him over a "medical condition" on Halloween night, which they accepted. On the night, Mr. Wolf stays in with Beast Boy and became more worried as time goes by. At the struck of full moon, he turned into a werewolf and goes on a rampage around the city before getting subdued by the Titans, using pizza as a trap. His condition was eventually revealed to the Titans on the morning after and he hoped to see the Titans again in the following month.
In "Secret Santa", Mr. Wolf tries to purchase a GameStation X console for his nephew, when Billy Numerous jumps in to steal the game set and tears the box apart. The last console (originally a Secret Santa gift from Robin to Beast Boy) was given to Mr. Wolf as Titans felt that he needed it more.