Wikia

Headless Horseman
The Headless Horseman as seen in The Elder Scrolls V: Skyrim.
Race	Ghost
Gender	Male
Level	Invincible
Class	Warrior
Faction	Ghost
Rank	Legendary Ghost
Essential	Sometimes
Ref ID	FF004EA8
Base ID	0010B302

The Headless Horseman is a headless, horse-riding ghostly specter who can be seen riding around Skyrim at night, or staying at Hamvir's Rest at day, facing its cemetery. He will spawn randomly anywhere in the world between 10:00 p.m. and 5 a.m. He will occasionally stop to let the player examine him and then continue riding. The Horseman performs no actions, and cannot be harmed. The Headless Horseman is also not connected to any main quests or side quests.

Currently, the only things that the Horseman has uttered is "Finality", "Such an abrupt end to our game", "Who dares disturb my rest?", "You are not welcome here" and "All the living shall fear the dead.". If you continue to follow him, he will normally lead you to Hamvir's Rest. There you can find three skeletons, a leveled Draugr, a master-level chest, as well as a couple of items in the area. If you fast travel directly to Hamvir's Rest, the Headless Horseman can be seen there during daytime. He will stand at the entrance of the cemetery and will not move until you get out of his sight.

Known Quotes

"Finality."
"Such an abrupt end to our game." - Upon entering Hamvir's Rest with the Headless Horseman and killing something that is chasing him
"Who dares disturb my rest?" - Upon encountering the Horseman.
"You are not welcome here." - Upon entering Hamvir's Rest with the Horseman.
"All the living shall fear the dead." - Rarely said when the Horseman is watching the player fight undead.
"You will join the dead." when in combat.

Known Spawn Locations

Around the farms and stables in the hold of Whiterun from 10:00pm to 1:21am. (Usual)
Coming down the road from Statue to Meridia, heading toward and over the Dragon Bridge at around 4:38am, 27th of Heartfire. Also on the 5th of Heartfire at 5.03am
On Morndas (Monday) at 2:15am, 2nd of Sun's Dusk.
Road leading from Anga's Mill to Forsaken Cave at 4:35am, 5th of Sun Dusk.
Road between Falkreath and Helgen at 10:20pm, 24th of Last Seed.
Road between Falkreath and Helgen at 2:40 am, 27th of Last Seed.
Road by Honningbrew Meadery, Tirdas 5:01AM 18th of Last Seed.
At Dragon Bridge, heading South at 10:49pm, 4th of First Seed, also 12:08am, 24th of Heartfire, 12:42 AM 10th of Evening Star and 11:30am 7th of Heartfire.
On the road north of Gloomreach traveling up the pass at 11:28, 24th of Last Seed.
At the signpost immediately south of Falkreath Stormcloak Camp at 11:59 PM, 10th of Frostfall.
On his horse near the entrance to Labyrinthian at 5:37 AM, 25th of Morning Star.When here Frost Trolls react by chasing and banging fists on ground.
The road that leads to and around Fort Kastav.
The road the leads to Salvius Farm from Kolskeggr Mine at 2:30 am of First Seed.
At around 11pm 5th of Sun's dusk from Blind Cliff Cave to Salvius Farm he comes about and double backs as he nears the farm, he runs on the same road till he crosses the bridge near Kolskeggr Mine.
Road leading from Steamcrag Camp to Kynsegrove, Eastmarch.
On the road along the northern coastline between Broken Oar Grotto and the northeast exit of Solitude at 11:45 pm.
Hamvir's Rest on foot running southeast, and on horseback.
On a path between Morthal and Labyrinthian. Appeared around 12:15am, Loredas, 5th of Sun's Dawn. (*Seems random. When loading earlier save then waiting for 12 to 24 hours he did not reappear)
The road between Markarth and Falkreath.
North of Robber's Gorge heading south on the road riding his horse at 5:00 AM 7th of Heartfire.
In the forests surrounding the Lord Stone.
Outside the main entrance to Solitude.
On the road heading south near Wolfskull Cave and the Statue to Meridia.
The road just north of Rorikstead, heading south.
On the way to Dustman's Cairn.
On the road near The Steed Stone.
East of Helgen.
The wilderness north of Riften.
Going towards Falkreath just past midnight of the 15th of Evening Star.
On the path outside Fort Greymoor at 11.30 (found after killing Agnes for a Dark Brotherhood Contract).
- Also on the path just west of Fort Greymoor (travelling eastwards past its main entrance, then taking the northern path when it forks into two) at about 2:30am, 21st of Mid Year. [I have not killed Agnes and first saw him long before I started the Dark Brotherhood quest line.]
Riding south over the bridge at Dragon Bridge, 12:41 AM, 28th of Heartfire.
Headless Horseman seen during the day.
Added by Kruho
Riding east past Reachwater Rock at 3:00 AM, 5th of Morning Star, and at 11:07PM, 29th of Second Seed.
Found south of Dawnstar near the Windward Ruins on Middas, at 3:00 AM, the 30th of Heartfire and rode to Hamvir's Rest and disappearing at 6:30 AM
Going from Dawnstar to Labyrinthian at 4:45 AM.
Heading South-East along the road past Nightgate Inn around 10:30 PM, just after killing Balagog gro-Nolob for the Dark Brotherhood quest Recipe for Disaster.
He can be seen during the day as well at 2:55 PM in front of Hamvir's Rest
Near Shadowgreen Cavern near 1:00 A.M.
On the road from Helgen to Ivarstead.
Exiting Winterhold around 3:00 A.M. Followed until eventually vanished near Valthiem Towers around 11:00 A.M.
Between Heartwood Mill and Faldar's Tooth around 1:00-1:30 AM.
Old Hroldan around 4:00-5:00 am.
On the road from Whitewatch Tower to Dawnstar (if you do the mission glory of the dead and follow your shield siblings it is that road that you can encounter him)
Near Markarth just past midnight on 22nd of Evening Star
Outside Blind Cliff Cave at 2.06am (Morndas)
Dragon Bridge at 5:26M Sundas 16th of Sun's Dusk. Saw him right after fast-traveling there.
Outside of the Thalmor Embassy on the road going west then a u-turn back east into solitude.
Road between Helgen and Ivarstead, south of the Throat of the World, at Middas, around 4:00 a.m., 2nd of Heartfire

Trivia

If NPCs pass right by The Headless Horseman, they will never talk to or about him.
The Horseman is never mentioned by anyone in major towns, suggesting not many know of his existence.
In rare cases, wild animals can be seen attacking the Horseman, although they cannot harm him.
The Horseman is possibly the ghost of Hamvir, as he leads the player to Hamvir's Rest.
The Horseman's appearance is completely random and unscripted. A player who has played for over 200 hours may have not seen him at all, yet, a player just starting the game and going right to exploring may see him.
The Horseman could also possibly be the spirit of Ragnar, as lyrics in the song "Ragnar the Red" that bards sing say "Who came riding to Whiterun from ole Rorikstead" and "When his ugly red head rolled around on the floor", referring to Ragnar's decapitation.
Hamvir's Rest is located North of Whiterun, where Ragnar was buried. This is another possible hint that the Horseman's true identity is Ragnar.
The Horseman is seen many times near Rorikstead traveling the direction to Whiterun, strongly indicating his true identity may be Ragnar.
It is recommended to not have a Follower attack him, as, due to his invincibility, the Follower will continue to attack him and not stop until killed or if the player reloads a save.
Sometimes, whilst following the Horseman, he will utter the word 'finality' in a spectral-sounding voice, quite like that of Peryite. The reason he says this one word is unknown.
The Headless Horseman may not be headless anymore if the player uses console commands and equips something on him, giving him a head.
If looked at closely, one will notice that the Horseman has a ghostly two-handed axe on his back. When the player gets to Hamvir's Rest from the Horseman's lead, the player can find a match of this axe, which is the Iron Battleaxe, further suggesting that he is a 'resident' there.
Other notable loot in Hamvir's rest are a skull, a random helmet with a random enchant, and a few other minor weapons.
Sometimes, the Horseman is spawned off of his steed, chasing him.
Bandits will try to attack him.
Contrary to popular belief, it is not possible to talk to him even if the player has consumed the 'Philter of the Phantom' or has used the Shout 'Become Ethereal'. The Horseman may say pre-packaged lines similar to those of any other ghost's, but that is all.
Sometimes the headless horseman will spawn without a horse and will instead sprint indefinitely towards his goal.
Using the console commands "killall" may be used to slay the Headless Horseman. He will drop a Steel Battleaxe.