His three exclusive missions are only available in the Limited Edition pre-order version of the game, which also adds 'The Impaler', a nasty harpoon gun. Both are on show in thisfrom Ubisoft.
Personally I'm of the opinion that anyone who uses the phrase "awesome sauce" needs to be kicked into a river, but at least the harpoon gun looks like lots of fun. New Far Cry 4 animal, too! Turns out it's best not to stand in front of an annoyed rhino.
Hurk's missions in Far Cry 3 were a bit... lame, to be honest. Hopefully Ubisoft has upped its game for these ones. I mean, you can't promise hordes of monkeys and then just half-ass it guys.