Tuten'kashSummon the first boss in Razorfen Downs by ringing the gong in the boss' chamber. The first two times the gong is rang, waves of spider adds will come into the room from either side.
The third time you ring the gong, the boss is summoned. Killing Tuten'Kash is straightforward, and many groups may not need to worry about dispelling the Virulent Poison or decursing Curse of Tuten'kash.
Plaguemaw the RottingIf you choose to escort Belnistrasz while in Razorfen Downs, then Plaguemaw will be presented as the final boss of the event. The boss is simple and is the easiest part of the escort itself.
Managing the multiple adds before him is the challenging part, as you need to keep Belnistrasz protected from mobs which spawn quickly. You cannot heal the NPC, be very careful holding threat off him.
Mordresh Fire EyeMordresh is a caster skeleton boss which you encounter on top of a pile of bones, surrounded by non-elite skeletons. Groups should AoE down the non elite and then focus DPS on Mordresh. He does not have very high armor, so this fight is easy for a balanced group composition.
RagglesnoutRagglesnout is a rare Quillboar mob who casts shadow spells, heal, and mind controls. This fight requires other members to fill in healing or picking up the boss if your Tank or Healer become affected by Dominate Mind.
GluttonThis abomination patrols below The Spiral of Thorns. The fight is a tank and spank.
Amnennar the ColdbringerAmennar is a servant to the Lich King, and the final boss of RFD. The boss casts frost spells and a knock back. The group should stack up behind the boss while the tank faces him towards the tent where he spawns. Interrupting Recipe: Ghost Dye and avoiding summoned Frost Spectres while maximizing DPS will bring this fight to a close with no issues.
Lady Falther'essLady Falther'ess is a boss that only shows up during the Scourge Invasion. She may silence people so watch your health throughout the fight. Apart from that it's a very straightforward fight.