I happened to turn the radio on in the middle of the elephant joke and I could tell right away it was one of the ghost-written stories that he supposedly read in the newspaper. It's funny how ridiculously obvious they are, he's a terrible actor and he can't read anything without stumbling over the words.
Howard: Gary drank a pound of elephant coffee....... Now his mouth just....
Robin: CACKLE, HOWARD, COFFEE DOESN'T COME FROM ELEPHANTS, IT COMES FROM A BEAN. CACKLE CACKLE
Howard: Now his mouth just smells like elephant shit.