Back in the day my brother and I used to play a decent amount of Dungeons and Dragons, one of the games we played being the Cosmofantasy, Spelljammer. It had it's own neat quirks, and I was reminded of our good times after reading this bit on creepy looking hippos over at Archy. The Giff, giant Hippo-men with an affection for firearms were one of my brother's favorite races to spin into the nightly fun, and I can't help but think these findings would fit perfectly in those themes.
Or maybe it was just King Hippo from Mike Tyson's Punch-Out! Hard to say.