I'm almost afraid to ask, but what is a Butterburger?

It's not as bad as it sounds. This is from an employee at Culvers, "The only butter added to a ButterBurger is a small amount placed on the crown (top) of the bun."

What's a Culver's?

Culver's is a mid-western fast food chain that uses fresh and local ingredients. I believe they started in Wisconsin and have spread about via franchises since. They serve custard instead of ice cream.

Very yummy. It's been a while since I last went.