I sang the song around a beer keg as a Kappa Alpha fraternity pledge in the 1950's at the University of South Carolina.
The verse I remember dealt with the horny skinned rhinocerous
..." step right up ladies and gentlemen and see the horny skinned rhinocerous. How do the natives kill the horny skinned rhinocerous??? Lift the tail and the arrows go in one by one" ...and "we are off to the Hamburger Zoo to see the elephant and the fighting kangaroo..."etc. Brings back good memories of good times.