Shadowmere (Oblivion)

 is a horse that appears in both The Elder Scrolls IV: Oblivion and The Elder Scrolls V: Skyrim.

Characteristics
Shadowmere is a purple tinted horse with glowing red eyes. Once belonging to Lucien Lachance of the Dark Brotherhood, Shadowmere is passed on to the player after completion of The Purification quest. Shadowmere is aggressive, and cannot be killed; she can only be knocked unconscious, this is a popular feature with players because of their ability to store an indefinite amount of items in Shadowmere while she is unconcious (see glitches). She is also one of the fastest horses, and can climb hills the player could normally not.

If she is knocked out, she will get up after a short while (About 30 secs). If you leave her behind and decide to walk on foot, you will be able to find her again back at Fort Farragut. If you cannot find her at Fort Farragut on the PC version you can use the console (~ on keyboard) and type "player.MoveTo 32BF5" This will move you to Shadowmere, which helps when it would take weeks for Shadowmere to get to Fort Farragut. She can also be armored if you have downloaded the official mod from Bethesda, but she then loses her "Essential NPC" status.

Due to Shadowmere's inability to be killed and her aggression towards anyone attacking you, she is a valuable ally in a fight. Her attack is of moderate strength, though, but if nothing else she can distract the enemy for you.

Glitches

 * Exploit: Shadowmere can also be used in an unusual exploit to carry an infinite amount of items. Simply knock out Shadowmere and quickly put the items you want stored on her corpse. To get the items back, knock Shadowmere out again.
 * If you punch or attack Shadowmere with a weapon directly it may be registered with any, or all, guilds the player is in to say that the player has been caught stealing, assulting or breaking a tenet of the Guild. In some rare cases, mounting onto shadowmere can break the tenet of stealing from a fellow guild member.
 * Glitches may happen with horses in general. This was experienced with a Chorrol or Cheydinhal horse just north of Memorial Mine with no Cowl of Nocturnal. After leaving the cave, a sword was equipped then was I barred from the Fighters' Guild, Mage's Guild and Thieves Guild.
 * Another glitch that may be encountered is that when you try to mount Shadowmere, the game will stop for a second and you will be somewhere seemingly glitched underground. You can exit by fast traveling, and when you do you will be riding Shadowmere. This glitch can also be encountered on normal horses. Sometimes you can get off your horse but if later you fast travel your horse will stay where you left it. It may travel with you but no longer belong to you, or another possiblity is Shadowmere will disappear.
 * Because of Shadowmere's inability to be killed you can effectively increase your perks by continuously attacking her. This works with one handed, two handed weapons, archery, and all of the spells.

Skyrim
Shadowmere also appears in The Elder Scrolls V: Skyrim.

Here you can see how to obtain her.

Characteristics
Shadowmere is given to the character a few quests into the quest-line of the Dark Brotherhood. During the Quest The Cure for Madness, the Sanctuary-Leader Astrid wants you to follow Cicero, the Night Mother's Keeper, to the Dawnstar sanctuary as swiftly as possible. To that end, she gives you Shadowmere, whom she calls "one of us" (oddly enough, Astrid calls Shadowmere a "he" even though Shadowmere is identified as a "she" by Lucien Lachance. Most likely this is because Shadowmere is a spirit and takes on the form of a male, due to the horse species being different to those in Cyrodiil). His first appearance outside the Sanctuary is very dramatic, and clearly shows that Shadowmere is no common horse. If you have summoned the Spectral Assassin (more commonly known as Lucien Lachance), he will greet Shadowmere as an old friend. Shadowmere is the hardiest horse in Skyrim and will fight in the same manner as a companion. As with any horse, Shadowmere allows the player to climb hills that are normally unscalable.

Comparitive to The Elder Scrolls IV: Oblivion Shadowmere is rather unexceptional. In Oblivion, Shadowmere far out-paced the Black horse, whereas in Skyrim he is not much better. This may be because Skyrim horses are smaller and more stocky than those in Oblivion, as described in-game: "The horses in Skyrim are hardly and strong, what they lack in speed they make up for in endurance". It may also be because of "horse-sprinting," and how Shadowmere's stamina is much greater than that of normal horses.

Unlike Oblivion, Shadowmere can be killed if he suffers a long fall. Shadowmere has quite a lot of health, and regenerate health very fast.

Glitches

 * On occasion, when you are standing in front of the pool from which Shadowmere is supposed to spawn during The Cure For Madness, you will hear Shadowmere rising out of the pool and then neighing, but he will not actually rise from the pool, effectively making him impossible to ride or otherwise be able to ride him as he will be trapped. However, Shadowmere wasn't actually prevented from spawning; the scripted event that makes him rise from the ground never occurred. So a good fix for this would be to wait until the quest Death Incarnate when there are enemies near the pool and bring one of them close to Shadowmere. With luck, the enemy you are fighting will lure Shadowmere out of the area he is trapped in and you will be able to climb on his back and then ride him whenever you wish.
 * This glitch can also be fixed by simply fast travelling to the where you bought your current/last horse. Shadowmere should be there for a split second before teleporting to the pool in front of the sanctuary. Just fast travel back to the sanctuary and get on him. He will then fast travel with you and behave normally as if this never occured. If this doesn't work, just try going to all of the stables before going back to the sanctuary.
 * Normally, horses are quite slow swimming in water. However, if Shadowmere is in water while you are riding him, you can make him run as if he where on land. Just unmount and re-mount yourself on him and you'll be able to run on water.

Appearances

 * The Elder Scrolls IV: Oblivion
 * The Elder Scrolls V: Skyrim