Start with the obvious chorus, and work from there!

The song of Owen, the hippopotamus (Also known as 'Augustine'!) *BG*

Mud, mud, look at that mud
Ain't seen nothing like it since Noah had his flood
You may think I'm barmy,
I surfed that tsunami
Now call out the army
To clear up this mud!

Nigel (I have this very Pratchettian image of a single hippo surfing on the back of a tortoise!)