Tim

Tim is a Caster skeleton found in the underground. He can be recognized by his Wizard Hat. Just like any other caster, he will randomly teleport himself to a visible part of the screen after shooting three projectiles. Tim was added as a rare spawn during the 1.0.3 update.

Finding Tim
You can find Tim around Lava level in caves although it may take some time for him to appear.

Trivia

 * His name is most likely a reference to Tim the Enchanter from Monty Python and the Holy Grail.

Drops
Wizard Hat