It has to be at least a 4lb worm. Length doesn't matter.

A little boy boards a public bus and sits down right behind the driver.

He begins to speak: "If my mom was a cow and my dad was a bull, I'd be a little calf. If my mom was a hen and my dad was a chicken, I'd be a little chick. If my mom was a deer and my dad was a buck, I'd be a little deer. If my mom was a duck and my dad was a goose, I'd be a little duckling."

After listening to the boy rambling on and on in the same manner for a while, the bus driver begins to get annoyed.

He turns around and says to the boy: “What if your mom was a drunk and your dad was a bum?”

In an instant, the boy responds: “I’d be a bus driver.”

The bus driver probably should have seen it coming!