Lok Tar Ogar, Victory or Death is an Orcish mantra/slogan.
The Horde consists of various races. Unless they are Orcs, they wont be LoKtar Ogaring anytime soon.
For example:
a) I play a Tauren, I don't Lok Tar Ogar
b) My warchief is an Undead, She doesn't Lok Tar Ogar
c) AU Nerzhul is not part of the Horde, but as an Orc he does Lok Tar Ogar
The more you know.