Unlock Location:
- Progress through the story until reaching Dominion Region.
- You will find a Side Quest called "One Slimey Issue" in the Fades District.
- Complete the Quest and at the end you will find Bio-Thresher Omega.
Farm Method:
- Defeat Bio-Thresher Omega.
- After use the Encore Machine nearby to reset the fight.
- Repeatedly defeat Bio-Thresher Omega until
Bugbear drops.