Professor

The Professor is an NPC that will spawn once the following conditions have been met: If the Professor is killed, he will only respawn if the above conditions are met again. He uses Carrot to defend himself.
 * There is an empty house.
 * Wall of Flesh has been defeated.

Names
The Professor can have the following names:
 * James
 * Harold
 * Steven
 * David
 * John
 * Brus Bunner
 * Alfred
 * Rizo

Quotes

 * "Don't pay attention to my appearance. This is just the result of a failed experiment."
 * "What do you have? Carrot? Oh, never mind."
 * "Imagine that in all those rabbits that you have killed were imprisoned soul of common people! Just think about it."
 * "Someday we'll all get into the warm embrace of death. Bring me some more carrot soup before this happens."
 * "Magic allows you to do what cannot be done scientifically. The main thing is not to overdo it, if you know what I mean."
 * "I don't like people that like how wizards get rabbits out of their magic hats. It's horrible!"
 * "I studied the anomalies in this world long time ago. Exactly during this I became the anomaly myself. Funny."

Trivia

 * His dialogue suggests that he was originally a normal scientist studying anomalies.
 * It is also stated that his rabbit-like appearance is due to a failed experiment.