Cadmium

Nybenhorn are considered dangerous... they're the opposite of you're graceful unicorn they live in moors not glades they eat meat not flowers or fruit, they're pack hunters... and they eat people... at least that's what's thought in Ashmire Moors that home the mire elves a brash folk who respect the creatures and view them as souls taken form... you can either be a nybenhorn yourself or mayhaps a naive explorer seeking to take a steed that craves the flesh of the fallen (Nybenhorn may be already a thing but I genuinely came up with this on my own so enjoy)