The hippopotamus is quite a formidable animal. They are semiaquatic relatives of whales, dolphins, and porpoises.
Their porcine appearance can be somewhat misleading. They are native to rivers, lakes, and mangrove swamps.
They give a disarming appearance of retreating peaceful gentleness.
I have witnessed them in attack mode.
The adults have large chisel shaped teeth which are feet long. It is my humble opinion that if they want you over some offense that you will be had one way or another.
Their sanitary habits are a bit distressing. They like to swish their tails and spread feces in their water habitat and I imagine it is healthy for the biosphere in general and nourishing to plants in particular.
Suffice it to say I'm glad I do not interact with them on a regular basis.
Today is World Hippo Day. Each February 15th we observe the hippopotamus in all it's glory and encourages people to conserve them as a species.
Personally, given their propensity for fierce attacking behavior I'd just as soon not get a hippopotamus for Christmas if you don't mind.