If

A little kid walks into a city bus and sits right behind the driver and starts yelling, "If my dad was a bull and my mom a cow I'd be a little bull".

The driver starts getting mad at the noisy kid, who continues with, "If my dad was an elephant and my mom a girl elephant I would be a little elephant."

The kid goes on with several animals until the bus driver gets angry and yells at the kid, "What if your dad was a drunk and your mom was a prostitute?"

The kid smiles and says, "I would be a bus driver."