I am borrowing the following story of why Hutto has hippos from Scout.com
One can only guess what the rancher thought when he came upon a hippopotamus submerged in the muddy waters of Cottonwood Creek. After all, hippos don’t normally inhabit Texas. As this event took place in the rural town of Hutto in 1915, the rancher might not have even known what kind of animal he was looking at.
Having escaped from a circus train that had stopped in Hutto for repairs several days earlier, the rouge hippopotamus made its way through farm fields, devouring crops and leveling others, until it reached nearby Cottonwood Creek. There it happily embedded itself into a muddy wallow, content never to leave. Once the animal was finally discovered, then came the almost incredulous task of removing it. This proved no small feat.
The misplaced hippo caused such a stir that, years later, the Hutto school system adopted the hippopotamus as its official mascot.
Well the whole town has gone to decorating with Hippos. They are everywhere, so we set out to hunt them down. Here are the ones we found.
FunStuff 