Ancestral Grudge (Hate Greenskins) Dwarfs hate all types of Orcs, Goblins and Snotlings, including Night Goblins, Black Orcs, Hobgoblins, Gnoblars... In fact all greenskins of any description!
Unbreakable Some creatures are utterly fearless and will never give up a battle, no matter how hopeless the situation might be. This could be because of the troops' extreme bravery, or because the creatures fighting are not truly alive.
These troops never break in close combat, and they are also immune to panic, terror and fear or any other Psychology rules.
If defeated in close combat (even by fear-causing creatures that outnumber them) unbreakable troops continue to fight on regardless of results.
They may never, however. declare that they are fleeing as a charge reaction, as they will literally die fighting under any circumstances.