Slabhide

Slabhide is the second boss of the Stonecore.

Adventure Guide
''With his powers as the Aspect of Earth amplified by the Old Gods, Deathwing easily swayed Deepholm's stone wyrms into serving the Twilight's Hammer. One of the most ambitious of these creatures, Slabhide hopes to earn Deathwing's favor by exterminating any intruders brazen enough to enter the Stonecore.''

Strategy
The approach to this boss will entail having stalactites falling in your path. Once you reach an open space, you will have to wait for Slabhide to catch up with you.

Phase 1
This is a ground phase, Slabhide will randomly cast Sand Blast which causes a frontal cone of damage; this should only hit the tank. In addition to this, he will also cast Eruption on random raid members. This causes a dust effect at your feet, you should move out of this as soon as you see it. After a few seconds this will cause 10,000 damage and create a lava pool which will deal an additional 5,000 damage per second to anyone standing in it.

Phase 2
When Slabhide flies up into the air, he will cause stalactites to fall among the group, you should avoid these as well as any lava pools that have not despawned. At the end of the phase, Slabhide will come back into the ground phase. However, the stalactites will still be present. Phase 1 will have the same mechanics, but the stalactites will hamper the player's line of sight causing issues with healing so awareness of positions of the tank/healer is required.

Heroic Difficulty
In heroic mode, the fight stays the same, but after the initial air phase Slabhide will start casting Crystal Storm, an AOE effect that must be avoided. Hiding behind the stalactites dropped in the air phase will allow you to avoid the damage from these. However it is worth noting that this appears to not be effective if you are still within melee range.

Since it is still very easy to go out of the healer's line of sight while hiding from Crystal Storm, it is a good idea to mark the tank or healer so that as many party members as possible can join up in one place.