Bestiary unlock for Zombie
Order EditKill the level 36 zombie Wulgrig in Cinderfall, located at 44k, 2.5k.
To get to Wulgrig, enter the Palik Tunnels and go north at the first junction, descend the ramp, and go left. In the first room you reach there is a "Pile of Rocks" behind a column on the left. Interact with them to spawn Wulgrig.
If the pile of rocks is not interactable (see below) then follow the directions given for Destruction players, they will work for Order also.
You can also just simply take quest(Belated Lament) from Dwarf(Scout Volgrig) you meet on the way and then on 2nd stage of Quest the "Pile of Rock" will be interactable and Wulgring will spawn.
Destruction players cannot interact with the rocks, but after approaching them a few times he spawns (this is confirmed). All you need to do is stand around near the Pile of Rocks (within about 30 feet) and he will eventually spawn.