What does Horrors in the Highland reward?

Horrors in the Highland gives a choice of Ironwood Destroyer, Curl of Life, Hornbeam Heft, 6,150 experience.

Where does Horrors in the Highland start?

Rethiel the Greenwarden in Wetlands offers it.

The quest log lists it at level 31.

Yes. Its quest id is not in Classic Era, so it is part of what Forever adds.

World of Warcraft: Forever · quest · level 31 · new since Classic Era

A level 31 quest in World of Warcraft: Forever, offered by Rethiel the Greenwarden in Wetlands. Recorded by 7 players running the addon.

Item	Given	Item level	Vendor sell
Ironwood Destroyer	as a choice	33	63s 40c
Curl of Life	as a choice	33	1g 7s 9c
Hornbeam Heft	as a choice	33	16c

What does Horrors in the Highland reward?: Horrors in the Highland gives a choice of Ironwood Destroyer, Curl of Life, Hornbeam Heft, 6,150 experience.
Where does Horrors in the Highland start?: Rethiel the Greenwarden in Wetlands offers it.
What level is Horrors in the Highland?: The quest log lists it at level 31.
Is Horrors in the Highland new in WoW Forever?: Yes. Its quest id is not in Classic Era, so it is part of what Forever adds.

What sells at this level, and what to keep from these rewards, is in the level 30 to 40 gold guide.

Source: what players running the addon saw in the quest windows; the quest text itself stays in the game. Every quest seen · Wetlands