Timmy is a neutral ghoul encountered by Prince Arthas and Jaina Proudmoore in Andorhal in Warcraft III: Reign of Chaos during Chapter Four of the Human Campaign called "Cult of the Damned". Timmy is kept in a cage at the center of Andorhal and can be freed by destroying it. Timmy is a Neutral being, so he can only be attacked with the Attack-button and then Left-click on him. He can be killed and drops the Ring of Superiority.
It is speculated by some that the ghoul Timmy is in fact Little Timmy transformed by the plague, and also that Timmy the Cruel in World of Warcraft is the same ghoul. However, Little Timmy is seen later selling ice shards, and even later on Theramore with his mother further dampening this theory.
Warcraft III designer David Fried commented on the matter:
"Timmy got used a few times because multiple designers end up making the same references in different areas. Tim Campbell was the level designer who put the original Timmy into Warcraft III (he's part of a quest if I remember correctly), and another level designer, Dean Shipley put the undead ghoul Timmy in the later level.
The WoW quest designers were not the same designers from Warcraft 3, so it's not surprising that things got mixed up, and thus you have Schrodinger's Timmy, who is simultaneously alive and undead".