Force vampire

The Force Vampire, formerly known as Jedi Knight Tel Angor, was the result of the Order of the Silver Jedi's experiments into creating a living symbol of the light side of the Force. Unfortunately for the Order, the experiments had the exact opposite effect; rather than Angor drawing on the Force to bolster his abilities, the dark side corrupted him completely, turning him into a hideous creature that fed on the Force itself, and indeed needed it to survive. Angor ceased to be himself and became the Force Vampire.

Text and facts from the “Force vampire” article on Wookieepedia, licensed under CC BY-SA 3.0. Modified for this site.