Can you tell me a joke?

A boy gets on the bus and says "if My mom were an girl elephant and my dad was a boy elephant that would make me baby elephant" and he continued "if my mom were a girl Hippo and my dad was a boy hippo that would make me a baby hippo" that bus driver was annoyed and told the little boy to shut up, but the boy continued " if my mom was a girl bird and my dad was a boy bird that would make me a baby bird" the bus driver then yelled at the boy "OH YEAH, THEN WHAT IF YOUR MOM WAS A PROSTITUTE AND YOU DAD WAS AN F'n DRUNK" and the boy said " then that would make me a bus driver."