Quote Originally Posted by AtomicKitKat
You probably already know this, but real-life hippos are scary buggers in general already. Running faster than a man(NEVER stand between a hippo and his home pool), with teeth that will rip you apart(they're blunt, but the edges are SHARP), they actually kill more people than lions every year.
Oh, aye, they definetely ain't fat and jolly... well, jolly anyways.

So of course Hippos in D&D (Found in Sandstorm of all places) have a base speed of 20 feet ::)