Behemoth

The Behemoth is an Emblem Heartless that is found in Kingdom Hearts.

Design
It is based on Behemoths from the Final Fantasy series, large purple monsters with two bull-like horns and a lion-like body.

Kingdom Hearts
The Behemoth is one of the three powerful Heartless released by the Final Keyhole, which is also the Keyhole to Hollow Bastion. The other two leave to attack Neverland and Agrabah, while Behemoth remains and guards the keyhole. Other Behemoths are also found in the Hades Cup and End of the World. These Behemoths were repurposed as the Destroyed and Arch Behemoths in Kingdom Hearts Final Mix.

Kingdom Hearts
Despite their menacing appearance, Behemoth can be defeated relatively easy, compared to many other bosses. His only weakness is the small black horn on his head, which is more often than not out of the player's reach while standing on the ground. The trick is to jump on to the thigh of one of his hind legs and then further on to his back (or just directly onto his back, if possible), and then simply run up to the back of the horn to avoid falling off due to Behemoth's head movements. From this position, one can attack freely, and without the possibility of being attacked by Behemoth. If the player attacks the horn enough, the Behemoth will fall to the ground making it easier for the whole party to fight it.

Blizzard, Thunder, and Fire magic doesn't affect him. Also, when he charges up his energy ball rain attack (an orange ball will start glowing in between his horns) get under his back legs and stay there until the balls stop raining and then make a dash for the weak horn.

If the player cannot make it to the Behemoth's horn, a possible alternate strategy is to spam Gravity and its upgrades. Since the Behemoth is slow, it will almost always be hit, and given its high HP will quickly lose a lot of HP. This depletes Sora's MP quickly however.

Your prize for winning in Hollow Bastion and the first battle in End of the World is the Omega Arts accessory. Another appears in the Hades Cup, where victory over it earns you the Blizzaga upgrade, and a fourth appears in the area just prior to the Final Rest save point in End of the World.