The Beast

The Beast is a boss found in Upper Blackrock Spire. It appears to be a Core hound that has been captured by the forces of Nefarian for use in his breeding experiments. (Experiments on other core hounds could account for the creation of Chromaggus, a core hound-like dragonkin who is the second-to-last boss found in Blackwing Lair.)

At some point before he is encountered by a party, the Beast had swallowed Finkle Einhorn, a gnomish adventurer who has survived in the Beast's stomach for an unspecified period of time. Skinning The Beast will free Finkle.

Strategy
Essentially, a tank will need to keep aggro on The Beast at all times as he hits extremely hard and can kill a cloth wearer in 2 or 3 hits. The rest of the raid will want to DPS him. As long as the Main Tank can keep aggro (best to say the Main Tanks, since it is unlikely that aggro can be consistently held, due to The Beast's oft-cast fears and random charges) and you have sufficient healing, this fight should be a simple one. He may drop Finkle's Skinner, which increases skinning by 10, so anyone in the group with a skinning skill of 300 should roll on this if they don't have it already, otherwise it can be greeded. It is vital to have a player in the raid who can skin The Beast, as they can receive the Pristine Hide of the Beast and also reveal Finkle Einhorn, who is the start of a quest chain.

The Beast is shown to know 7 moves: Terrifying Roar, Flamebreak, Fire Blast, Summon Player, Fireball, Berserk Charge and Immolate.

Legend
Prior to Patch 4.0.3a, The Beast was very well know to Beast Mastery hunters, as it was the only pet in the game that retained the 'Level ?? (Boss)' tag even after taming. As this was changed by Blizzard, The Beast was most likely never intended to actually keep the boss tags in this way. Arguably in compensation for this change, Blizzard allowed many classic, level 60 bosses (such as Chromaggus and Buru the Gorger) to be tamed by Beast Mastery hunters.