Zil & Thungr has 4,200 health and spawns in the plains.
Spirit does nothing to it at all. Blunt, slash and pierce land at full damage, so that is what to bring.
Its hardest hit does 150 blunt, out of 4 attacks.
Some of what it throws is elemental, so fire resistance is worth having.
Of everything craftable, 
Frostfire Crossbow, 
Thunderblood Crossbow and 
Lightning Strike put the most damage through what it resists.
It always drops GoblinShaman_Hildir and 
Thungr Trophy.
Zil & Thungr is the paired Plains miniboss of Hildir's quest, fought at the Sealed Tower with Zil riding on Thungr's shoulders. The pair has 4,200 health between them, is immune to spirit damage, and resists nothing else. Killing the combined form always drops the Thungr Trophy and releases 
Zil, who fights on alone with 2,400 health of his own and carries 
Hildir's Bronze Chest. Both halves move at 5 meters per second walking or running, which is slow enough to kite if the tower has room.
It is a two-phase fight in one body: burst through Zil's barrier windows, dodge Thungr's three-slam rage combo sideways, and never stand in the fireball line while parrying the club. Frost slows the pair and neither resists it. Zil drops the chest, so the shaman is the actual objective.
With devcommands enabled, this spawns Zil & Thungr in front of you. The third number is the level: 3 spawns a 2-star.
Creature ID: GoblinBruteBros · all console commands and IDs