I've already killed Bloody Vrukwuk before, so when I saw him last time, I wasn't really into killing him, so I decided to try to kill Warchief Vatgit without Bloody Vrukwuk attacking me. I had to follow him around for a few minutes and he follows Warchief so closely that it was taking forever, but finally Warchief turned around when walking and just stopped, leaving Bloody facing the wrong way. This was perfect, so I killed Warchief and Bloody didn't attack me. However, Bloody didn't move anymore, at all. Within 30 seconds to 1 minute later, he just disappeared. I was like WTF? So I waited for Warchief to respawn and when he did, this time he had Fogweaver Mozzfuzz with him. That was bad@$$ so I did the same again. I managed to kill Warchief without getting Fogweaver's attention. Then he disappeared, just like Bloody. Then Warchief respawned a few minutes later, only this time he was alone...no Bloody Vrukwuk and no Fogwearver Mozzfuzz. :(
Also, about Eanderu Scholar's post right below mine, Ashmaker Gotblut is not a maintenance pop only, you just have to camp him for about 2 hours for him to pop. Trust me, I camp him all the time and he spawns. However I give up after 2 hours if he doesn't pop and just try later. He may be a pain to pop, but he eventually will.