Your mum is a black cow by Ice-T ft Tupac
Off the top of your head. Never use someone elses lyrics. If u cant spit your own then its not your game.
Check out anything by The Bloodhound Gang. They are hilarious. But bewarned it's not appropriate for children.
beak,eek,freak,geek,meek,peek,reek,seek,peak,weak. for more, google rhyming dictionary.