Ragefire Chasm is a low level instance found in the Cleft of Shadows area of Orgrimmar. The instance is pegged for players levels 13-16, which makes it the lowest level instance on either side, although you may enter at level 8. There are 4 farmable bosses in this instance of which 2, post Patch 2.3, drop blue or rare quality items. There is a 5th boss, however he is only available to Horde paladins as part of a quest chain which begins at level 20.
Rgefire Chasm is mainly a Horde instance due to the fact that it is in the middle of their biggest city. Though Alliance do come here because there are a few good twink pieces that drop.
In of patch 4.0.3a the recommended level for the dungeon was raised from 13-16 to 15-21. As of patch 5.0.1 the entire dungeon was redesigned, adding new bosses, npc's and quests.
This boss does not drop any rare loot, his purpose is merely to guard a corpse that horde players must interact with to complete the quest "Searching for the Lost Satchel".
Oggleflint is a pure melee boss with a cleave ability.
Oggleflint was removed as a functional boss in the 5.0.1 redesign. However, Oggleflint's body remains in the dungeon; this time, as a corpse dubbed "Hound Food". Players can find this coveted easter egg beset by a rotting carcass, near the Adarogg encounter.
Taragamen the Hungerer
This is considered the end boss for the purpose of the instance completion achievement. However he is more toward the middle of the instance, not near the end. He drops 3 of the 6 rare loot items in the instance. One of these, cloth bracer's named Crystalline Cuffs is a highly sought after twink item. His heart also is needed for the horde quest "Slaying the Beast".
Taragamen does a mix of fire damage and melee damage.
Jergosh the Invoker
This boss drops the other half of the instances rare items. One of these, Robe of Evocation, while not the best cloth twink chest, is still a very good piece for those who don't have the money to farm the auction house. Horde also must defeat him for the quest "Hidden Enemies".
Jergosh is a warlock type caster and does spell damage including a curse and immolate.
This boss drops no important loot, his only purpose is to die so horde can complete the quest "Hidden Enemies".
Bazzalan is a rogue type mob and does melee damage such as Sinister Strike.
Zelemar the Wrathful
This mob is only able to be killed when summoned by a Paladin with the quest "The Path of the Adept." Paladins need his blood to complete this lvl 20 quest to receive a rare quality weapon.
Adarogg, a Flame Hound ripped from the Firelands, now resides in the Ragefire Chasm. This boss replaces Oggleflint as the first boss of the dungeon, he drops the same rare loot as Oggleflint but is a much harder fight as he has separate mechanics such as Flame Breath and Inferno Charge. He is the first boss that needs to be killed to complete the quest "Animal Control."
Dark Shaman Koranthal
Lava Guard Gordoth