1. A pony with an extremely bad attitude to things (everything, everyone.) Also the word "Darkhearted" can be used when describing other animals (e.g Darkheartedduck)
2. a very awesome person who saw an Albanian guy kick a puppy twice.
Angelina Jolie rode to Hollywood on a Darkheartedpony on dismounting she tried to feel the Pony a carrot to which it responded to biting her fingers and face off. Then galloped away on a carpet of live Darkheartedrabbits.