Dr. Topper

Dr. Topper (who likes to be called Dr. T) is a green Hammer Bro. and a quizmaster who resides in Bowser's Keep. During the events of Super Mario RPG, Smithy's troops occupied the Koopa King's castle. Like many other members of the Koopa Troop, Dr. Topper switched allegiances (by his own free will or through brainwashing) and joined the Smithy Gang, instead of fighting the extraterrestrial forces. As such, the quizmaster was assigned to hide behind two of the six red doors in Bowser's Keep. Two of the six doors led to platform stages, two doors led to battle stages, and two doors led to puzzle stages. Dr. Topper was in charge of the puzzle stages. If someone could not figure out his tricky puzzles, he or she could not progress through Bowser's Keep.

Trivia

 * Dr. Topper wields a green-colored mallet.
 * Although he is a Hammer Brother, Dr. Topper works alone.
 * Another lone, quiz-hosting Hammer Brother (named Mr. Hammer) appears in Paper Mario. This quizmaster may have been inspired by Dr. Topper.
 * Dr. T could be a pun on Mr. T.