Eikthyr Trophy

This severed head oozes power.
Offer it to the Sacrificial Stones.
Overview

Eikthyr drops the trophy along with 

Placing the trophy on the correct hook grants Eikthyr’s Forsaken Power. When activated with the default F key, this power reduces stamina consumption for sprinting and jumping by 60% for 5 minutes, with a 20-minute cooldown. Some sources also note that the power affects nearby allies and that it reduces swim stamina use as well.
The trophy can also be used as a mounted decoration on an item mount. Like other trophies, it may be used to program a Ballista, allowing it to target Eikthyr trophy as a valid enemy category.
Eikthyr trophy is tied to several world progression changes through the boss itself. Defeating Eikthyr disables the repeatable event where Eikthyr rallies the creatures of the forest and enables The forest is moving... if 

Eikthyr can be summoned repeatedly at his Forsaken altar in the Meadows by offering two Deer trophies. A Vegvisir near the starting sacrificial stone marks the closest summoning location on the map, and multiple summoning altars can be found in the Meadows. In combat, Eikthyr uses three attacks and an environmental aura that darkens the area and stops rain: a ranged lightning beam, a large area lightning burst, and a melee antler strike. His trophy is therefore one of the earliest and most important boss rewards in the game, opening up both mining progression and the first major movement buff.
A few practical notes make the trophy especially useful early on:
- It can be mounted for base decoration.
- It can be used to assign a Ballista target.
- It unlocks a Forsaken Power that is ideal for early exploration, sprinting, and jumping.
- Since Eikthyr has no special resistances, his trophy is generally earned by a straightforward first boss fight rather than any special drop condition.
Eikthyr himself is likely a reference to Eikþyrnir, the stag of Norse mythology associated with Valhalla.
Official description
This severed head oozes power.
Offer it to the Sacrificial Stones.
Other entities of this type
- Abomination Trophy
- Asksvin Trophy
- Bear Trophy
- Blob Trophy
- Boar Trophy
- Bonemass Trophy
- Bonemaw Trophy
- Brenna Trophy
- Cultist Trophy
- Deathsquito Trophy
- Deer Trophy
- Drake Trophy
- Draugr Elite Trophy
- Draugr Trophy
- Dvergr Trophy
- Fader Trophy
- Fallen Valkyrie Trophy
- Fenring Trophy
- Fuling Berserker Trophy
- Fuling Shaman Trophy
- Fuling Trophy
- Geirrhafa Trophy
- Ghost Trophy
- Gjall Trophy
- Greydwarf Brute Trophy
- Greydwarf Shaman Trophy
- Greydwarf Trophy
- Hare Trophy
- Kvastur trophy
- Leech Trophy
... +26 (see sidebar for full list)