[patmcguire]

What's great about this analogy is that Unicorns are officially Bad News for dwarfs, and will frequently gore and trample everyone in your fortress to death.

[Natsu]

They're also valuable.

"Unicorn products are worth four times as much as domestic animals, making unicorn genocide in the name of profit an attractive proposition."

- DF Wiki http://dwarffortresswiki.org/index.php/DF2014:Unicorn