Big Boss of the Ynts, real big. Either he's angry at Klaymen for intruding into the Ynt domain, or Klogg has him under his control, too. We'll probably never know.
He's got a pretty touch shell and sharp claws. Gladly, before he can snap at you with his bigger claw he has to aim out carefully with his smaller one, best chance to flee!
To visit Glenn Yntis in his boss-level, survive the level Ynt Eggs.