Follower (Oblivion)

These NPS's will follow you into battle and will fight with you (the one exception is the Adoring fan. He only stands around to give you light in dark places with a torch . He will run from dangers, and thus will not battle). You may give them the commands "Wait" (to stay where they are), Follow (to go with you), and Go away (to have them leave).

A follower is a NPC who can follow the Main Character around the game world. The only known ones in The Elder Scrolls IV: Oblivion are
 * A Mage Apprentice (after completing "Confront the King"),Knight_dude.jpeg
 * A Dark Brotherhood Murderer (after completing "Honor Thy Mother").
 * The Adoring Fan (after the Arena's 'Grand Champion' fight).
 * A Knight of the Nine (after completing "Umaril the Unfeathered ").
 * A Flame, Frost or Storm Atronach (if you have the Wizard's Tower DLC).
 * Battlehorn Man-at-arms and Mage (if you have the Fighter's Stronghold DLC).

Temporary followers
There are some characters who follow you if you are doing their quest.
 * Martin and Jauffre during the Weynon Priory quest.
 * Mazoga During the Mazoga the Orc quest.
 * Maglir/Oryen,
 * Errthor (in place of the Mage Apprentice), Guilbert and Reynald Jemane
 * Umbacano and his bodyguard.

You also can have multiple followers or all (with the exception of the Apprentice and Erthor) at once, and 6 of them will not die. Also Velwyn Berinus, whom you get Berinus Manor in Anvil from, will follow you when you are going to cleanse the manor. There are possible others also. Various guards and Captains (such as Savlian Matius) follow you in the "Breaking the Siege of Kvatch" quest.

When you have four or more followers the game will give you the message "you have too many followers" but you can ignore that because it doesn't affect the game in any way. Followers are always Non-Essential characters, and may die. With the exception of the Knights of the Nine followers, they will eventually be replaced at the place where you got them. (as in the Kvatch quest, where guards can be killed off, especially if you are playing at higher levels).