Hadronox

From wow.incgamers.com

Hadronox is the second boss in Azjol-Nerub, a 5-man instance in Dragonblight. He is a huge spider, that is attacked my several small spiders as the encounter begins. It is advisable to start the fight while he is being damaged by these other mobs. When Hadronox kills one of these mobs or a player, he regains health, and when the encounter is over, any remaining small spiders will turn their attack onto players.

You can see videos of the full fight here.

Loot

Normal Difficulty

[Unknown Item: Spinneret Epaulets] Leather Caster Bracers
[Unknown Item: Life-Staff of the Web Lair] Caster Staff
[Unknown Item: Treads of Aspiring Heights] Melee Leather Boots

Heroic Diffculty

[Unknown Item: Grotto Mist Gloves] Leather Caster Gloves