If I can recall, it all started between Lead Tutor Jenni writing each of Staff Tutor Hillary's top 5 characteristics on the chalkboard. Hillary described herself as... It then boiled down to an elephant and horse to which Hillary decided horse because... horses are cool, I guess.
Soon, each available Staff Tutor joined in afterwards. Some of the ones I remembered was: Greg was a two-toed sloth (even though most of us thought he'd be a Labrador by just how cheerful he is), Talea was between an ostrich, because her sense of humor and silliness is a lot like how an ostrich looks, and a giraffe. I was a "rabbit riding a parakeet" only because we couldn't decide if I were a rabbit or a parakeet.
The only parameters were it had to be an animal in our world so sadly, unicorns weren't allowed. But if you wanted to be one so bad, you could always choose a narwhal, the unicorn of the sea.