Planning on eventually bringing an Absol forward from Pokemon Ruby into the current gen. At the bottom of that page, turns out it's a inspired by a rare creature from Japanese and Chinese mythology. To be sure, the Pokemon is a very sexed-up version of that thing, but Wikipedia says the sources don't agree on its appearance, so one horn and one extra eye is the simplest possible portrayal.

This is fascinating (how many other Pokemon are mythical creatures of good fortune?) and crosses the line from wanting this Pokemon on my team because of his good looks and high stats... to believing in him the way Ash believed in Pikachu.