Tera Walkthrough: Horned Horrors

Talk to Guard Taras, standing near the stairs to the Tower Base on the Island of Dawn to commence this quest. This is a level 5 quest.

Horned Horrors
I don't care what Dulari says, Walking trees are not natural in any way. And the ones here are even creepier than those by his campsite. Back home we've got nothing like these Horned Ghilliedhus.
Jirash got first pick of these assignments, and he doesn't care at all that I've got to push the ghilliedhus back from our perimeter as often as is necessary. You'd be doing me a solid if you could take out a couple while performing your own duties.

Accept quest. Your task is to kill horned Ghilliedhus west of the tower base. Open your quest log, and click on the blue monster name, "Horned Ghilliedhus", to mark their locations on the map. They are similar to the other tree monsters you killed in previous quests, only these are bigger. The same strategy applies - back off when they do their melee attack - you can tell this is happening when they swing their arms back. Kill four of them.

Return to Guard Taras to check in. He asks you:
"I've got something to ask you: did you think those ghilliedhus were more or less aggressive than the ones north of here? No real difference? That's what I keep telling them. The researchers are convinced that the ones around here are weakening in some way. Doesn't change our mission - anything threatening our base must be dealt with, as fast as possible."

Accept your reward of experience and gold. This completes the quest, Horned Horrors.