Just go out into the wild, kill a thing, raise it, ride it. Want to ride a zombie devilsaur? Go make a fucking zombie devilsaur. Who’s going to stop you, you’re a death knight. Just fucking do it.
It’s like the Scourge version of pet taming.
What if Tev was a dk with a phobia of blood?
I am pretty sure that he would have never made it out of his training in Naxxramas.