I had to vote for 'wombat'. For one thing, the name is silly but in that 'name is almost familiar because of a different but similarly named object' sort of way, like 'diphthong'. For another, I remember that for one season, I'm Sorry I'll Read That Again had a parody of adventure serials called "Curse of the Flying Wombat". My friends and I have so many running jokes because of that series that my vote wasn't really a choice.