Someone who enables the Bozo Explosion, either intentionally or due to their inexperience and incompetence.
The Bozo Explosion was possibly coined by Steve Jobs at Apple:
"Actually, Steve believed that A players hire A players—that is people who are as good as they are. I refined this slightly—my theory is that A players hire people even better than themselves. It’s clear, though, that B players hire C players so they can feel superior to them, and C players hire D players. If you start hiring B players, expect what Steve called “the bozo explosion” to happen in your organization." -Guy Kawasaki
My manager is the lead Bozo Bomber at my company. He makes sure everyone in the business is as dumb as a caveman, then he can swoop in like Superman and save the day. Man, does it make him look good. Terrible for the business though.