Fafnir (Act 5) Farming Location - Titan Quest: Ragnarok
Location: Fafnir's Cave
Closest Portal: Glauberg; run far north
Noteable Loot: He has a loot table on par with Surtr and is easier to farm depending on your build
Fafnir is a boss that only spawns on Legendary difficulty in Fafnir's Cave. This cave is in a hidden location which you have to visit during Act 5 to complete The Magic Cauldron Side Quest. If you'd like directions on how to reach this cave I recommend you check out that walkthrough as it provides step by step instructions. The closest Rebirth Shrine to Fafnir is just outside the cave, an extremely short run which is one of the biggest perks to this farming location.
Much like all of the other mega bosses in the game, Fafnir hits like an absolute truck and will be extremely difficult to farm except for the most over powered of builds. Thankfully despite his difficulty level, Fafnir's Mystical Orb has access to a very good loot table. Like the Freyja's Set pieces will only drop from the end game bosses of Act 5, Fafnir included.
Below is a list of all the attacks that you should expect Fafnir to use during your fight with him.
Recommended Resists: Fire, Vitality and Poison
Lava Blob: Fafnir throws a blob that creates a puddle that applies a Fire and Vitality damage DoT; only 5 Lava Blobs can be active at one time and he only uses this ability against ranged/casters.
Poison Blob: This is the Poison version of Lava Blob and it deals Poison damage over 6 seconds. Only one Poison Blob can be active at a time.
Tail Swipe: Circular attack that deals high Physical Damage as well as stuns anyone it hits for 2 - 4 seconds.
Death Vortex: Same attack Hades uses in Phase 2, they will be little vortexs that move around on the ground for about 10 seconds and deal high Vitality damage if you touch them.
Super Bite: Fafnir's standard attack that does high Physical and Pierce damage as well as applies a weaker Poison DoT.
The fight with Fafnir is a very hard one because the amount of damage he puts out is insane. Most melee will struggle to stand toe to toe with him and most ranged/casters will spend most of the time avoiding his blobs and vortex attacks. Builds with very high burst DPS will have the easiest time farming this boss. Pet builds will probably have the hardest time since Fafnir will wreck just about all pets very quickly.
Fafnir is vulnerable to Lightning Damage and has no innate resistance to Physical Damage. He has a small 10% Resistance to Pierce damage and Poison (20%) but that's it. Despite having almost no Resistances he has a gigantic health pool so the fight probably will be a few minutes long.