Quite possibly the best being in the Universe.
Created JTHM, I Feel Sick, Squee!, the BAC, Everything Can Be Beaten, and Invader Zim. Although IZ was a team effort over at Nick, Jhonen was responsible for the idea.
His hillarity is often confused with Roman Dirge and his work, which is similar but in my opinion, not as funny. And that guy was right, The Cat With the Really Big Head was written by Roman Dirge.
Jhonen Vasquez is the funniest man alive.