Murdrick Tardok
 

The NPC is able to see invisibility, so triggering the scripted dialogue isn't possible.

After you pull him, you have a certain amount of time to kill him, cause his scripted dialogue will trigger and once he finishes it he will de-spawn.

He still drops the head regardless if your able to trigger the dialogue before the pull.

Literally just did this tonight wouldn't start the dialogue until i started attacking him. Was about to kill him with a lvl 60 ranger solo without and despawning issues.

We were able to trigger the script today. So it does work. I'm sure its some sort of trigger and has nothing to do with whether Murdrick can see invis.

However, it was a bit tricky and took a while; I'm not sure what exactly we did that got it to work.

have always just killed him without any dialogue