I iz is a blob-like character of the species Zizz. He is the leader of all Zizzes, although it's a mystery how Zizzes can tell each other apart, for they all are pretty much identical (except for the occasional size difference). I iz was created back in, oh, say 1998 or so by Michael Mesorana (aka Tibby or Poofmeister), and stars (along with other Zizzes)in a series of short cartoons made by Will Buck (aka Vlad). See I iz's quotes below:
"But I iz whut you iz when we iz not me waz. Iz you?"
"I iz been done cut. Hey."
"Gimme that hat."
"I iz be not going to not no movies. I like to sit."
...And the number one, most famous phrase... the one that started it all...
"I iz who I iz."