Do you want to be able to have an permanent pet as a DK without even beeing speced for it?

If so, listen up

Found a small exploit that let's you to have a pet ghoul without having the pet unholy talent.

What you do is that you go to Grizzly hills, Westfall Bridage Encampment and find a boy named Squire Percy.
Be sure to either have a dual-spec with frost / blood as an offspec or be specced for one of them when you go there. If you have it dual-specced, change to that spec and speak to the boy. Tell him you want to use the stable function. You will see many empty squares that all tell you Empty stable slot. There should be a button saying "Purchase an additional stable slot", however if there isn't, relog as specced to the non-ghoul spec as many times it takes (took me 2 relogs) for the button to show up. When it does, buy an additional slot. Now the part where you actually get the pet:

Hold your left mouse button on the Current pet tab that seems to be empty and drag it to the slot that you just unlocked by buying an additional slot. Now simply close the stable, open it again, and drag it back from the additional slot to the Current Pet slot and voilá, your unholy pet ghoul will spawn next to you even if you're not specced for it!

If you or the ghoul dies, or you summon a new 1minute ghoul or you zone into arena, then you will have to go back to Grizzly Hills and get it from the stables.

Enjoy