Yama Tsukami

Yama Tsukami is the oldest creature known to hunters. It's skin is covered by Dragonmoss & Dragonwood. It has four tentacles and a pair of 'whiskers'. It drops Dragonwood and Dragonmoss as rewards. When enraged, its red eyes glow yellow.

Its classification as an Elder Dragon is simply due to the fact that it does not fit into any category, much like the Kirin. This mysterious creature's place in relation to other monsters is completely unknown. Although a tremendous size, it is able to constantly stay up in the air with no support. Its attacks are slow but devastating.

They seem to have a symbiotic relationship with Great Thunderbugs, which lets them rest inside Yama Tsukami's body until they mature. In return, the Great Thunderbugs assist it by attacking Hunters. These Thunderbugs can explode when they are near a Hunter, causing a good amount of damage to its target.

Trivia

 * Yama Tsukami first appeared in Monster Hunter 2 as the final boss. Although it wasn't included in Monster Hunter Freedom 2, he was added in the expansion game Monster Hunter Portable 2nd G as the HR8-HR9 Urgent quest.
 * It made its first U.S. appearance in Monster Hunter Freedom Unite.
 * Yama Tsukami is fought quite differently in Monster Hunter 2 and Monster Hunter Frontier than in Monster Hunter Freedom Unite. Originally hunters would chase him through the tower, fighting him at the spiral zones (Doubled in length for the fight) in areas 6 and 8, with the same moves Yamatsukami uses in MHFU. Then he will flee to the top of the tower where he gains a new set of moves, such as hovering high in the air and then slamming down in an attempt to crush the hunter. Your main targets now become his tentacles and whiskers, as Yama Tsukami's main body will be far out of reach. Yama Tsukami can also be fought in the town in both Monster Hunter 2 and Frontier. In MHFU, however, you fight him in a modified tower, with a flat ledge bordering a crumbling spire, where he will stay for the entire fight.
 * Although Yama Tsukami cannot be captured, the tranquilizer effect of the tranq bombs actually numbs it from flight and causes him to drop down. In addition, it drops a shiny.
 * To take advantage of Yama Tsukami's Tranquilizer weakness, throw 2 Tranq Bombs while it attacks with a Wind Tunnel (be careful, it is risky if you don't move out).
 * This requires 1 more Tranq Bomb for each additional time you want to tranquilise him.
 * If you choose to continue to attack Yama Tsukami on the floor of the tower, he will use the same attacks as he would on the top of the tower in Monster Hunter 2.
 * the only difference between his American and Japanese name is a space: Japanese: Yamatsukami: American: Yama Tsukami

Gameplay footage
http://www.youtube.com/watch?v=0HUd8gW9iWo