Meathook

1. This boss can be a real pain if you don't watch out for his Constricting Chains. These chains will deal 1,800 damage a second and stun you for 5 seconds. The chains do not always hit the target farthest from Meathook, they will hit a random target outside of his Disease Expulsion. You can line of sight this ability, so if you have a good tank try having him pull him out of the healers line of sight for a second.
2. Disease Expulsion is another ability he does which is an AoE disease spell, this spell will also silence for 4 seconds so be careful.

Salramm the Fleshcrafter

1. This boss is not too hard as long as your group watches out for his Corpse Explode which he will do on the ghouls he summons. Try to have the party spread out so it doesn't hit more then one person, putting stress on the healer.
2. Only other noteable ability is Shadow Bolt, which hits pretty hard and can not be interrupted. If you have a warrior then spell reflect it or if there's a shaman in the group use your grounding totem on it.

Chrono-Lord Epoch

1. A big problem with this boss is he charges the healer often, sometimes 3 or 4 times in a row, which can definitely kill them.
2. Curse of Exertion increases the cost of spells and abilities by 100% for 10 seconds. This can be removed, so if you're a mage or druid make sure you're ready to remove this.
3. Healing during this fight is slightly harder do to Wounding Strike, this ability does damage over time and reduces healing by 25%.
4. Time Warp will also be cast, this reduces attack,casting, and movement speed by 70% for 6 seconds.
5. If you can disarm then do it, it will stop a lot of his damage and help out the healer.

Mal'Ganis

1. Mal'Ganis is a level 82 elite with 505,538 health.
2. As of patch 3.03, if you kill him too fast he will get bugged and stuck at 1 health. Hope this is fixed soon!
3. The tank needs to face him away from the party, he will do Carrion Swarm this needs to not hit the party.
4. Mind Blast hits really hard, it can not be interrupted. However it can be grounded by a grounding totem, making the fight a lot easier.
5. Sleep like any other sleep will break on damage and lasts 10 seconds. On normal mode this can be dispelled, on heroic it can not be dispelled.