I Made a Food!

You get the achievement when you kill a Black Bile before killing Festerface.

To spawn a Black bile, Festerface needs to reach 100 energy. To do so you need him to not soak any puddles. When he reaches 100 energy he will spawn a black bile. The black bile reduces healing by 100% so make sure everyone is topped off. USE THE CANDLES ON THE WALL TO INSTA KILL EVERYTHING

Easy achievement.

Easy Solo for Level 120 Battle for Azeroth and Beyond...

1. Mythic Difficulty.

2. Festerface is up on a weekly rotation with other bosses. If it helps, he was up on the week of March 13, 2019 in the United States and the first boss I encountered in that instance.

3. Begin encounter, do not attack boss.

4. Boss starts spewing biles everywhere, just ignore.

5. Eventually boss will vomit, and an ugly Black Bile appears.

6. Kill the Black Bile. Make sure your attacks do not kill the boss before the Black Bile is dead.

7. With the Black Bile dead, attack and kill Festerface.

8. ?

9. Profit. Achievement Completed.

What I don't like about this achievement is you have to be lucky enough to get Festergut as a boss to spawn for you that week in Mythic. This is literally the last achievement I need for the Glory of Legion Hero. :\