A man walks into a bar with a lizard on his shoulder. He walks up to the bar and asks for a pint for himself and a half pint for Tiny, his lizard.
The barman looks a little taken aback but serves him and Tiny. Finally, curiosity gets the better of him;

Barman: Why do you call him Tiny? 
Man: Because he's my newt.

It pays to be prepared to teach newt, lizard and minute afterwards, but expect a few groans as the penny drops!