Disclaimer: This guide is no way meant to be perfect. It just provides a general idea of how to farm elite festerfang and why to farm. Sorry if a guide already exists.
1. Infested swamp
Tip 1. Stick close to boss
Tip 2. When you see white-ish circles from ground, go and stand inside those circles and avoid to attack
Tip 3. When see purple-ish circles below you, avoid to attack
Tip 4. When you see message "find safety if you can", find the colored circle for your class and stand in it. Mage on staff, rogue on bow-arrow, warrior on sword. Color changes. The three statues behind the map also display the color you need if u get confused.
Tip 5. You can ignore the small circles popping up in between. try to stick with boss in any corner.
Important Loot table: so far what I have seen others loot and looted myself are -- mire armor, mire amulet , arcane swamp thing ring, red raid coin, red raid coin bag.
2. Hydras bog
Tip 1. When boss is spawned don't just stand in plain sight. Boss can do range attacks with poison pools.
Tip 2. Try to avoid attacking boss when it is not vulnerable.
Tip 3. It is easy to attack tails but the time boss stays vulnerable will also be less.
Tip 4. Attack the heads on the adjacent sides of boss.
Tip 5. Heads on adjacent sides spawn alternatively.
Tip 6. Set a counter in your mind as to how long you can stay near boss when vulnerable.
Important loot table: mire armor, mire amulet, mire arti, red raid coin , red raid coin bag.