Proper Festergut Raid Guide:
1. Think of him as Patchwerk!
2. Add some spoooooores. Blame your retards which finally learned to move OUT the fire to move IN the spores (this could be the tricky part).
3. add some lolwutnevernoticed raid damage.
4. Now get your retards who get the spores to not clump with the other two retards with spores (together with 2. this could be even more tricky).
4a. Tell one of them to move into the melees, if no one is there.
5. threaten your DPS with FUCKING FIFTY DKP MINUS if they don't do appropriate DPS.
if you now compare patchwerk kills with T6 or some Outland Blues with festergut and T9-ish gear, it should be pretty much the same feeling.
6. Get one less tank but one more dps and tell the tanks to taunt at 9 stacks on them and blow their CDs at 3 stacks of the boss.
7. Get festergut's health <0 before he gets your raid's health <0. which will happen after 300 seconds.