Magmasaurs, gigas, rock golems, and velonasaurs all do pretty good or so ive heard while pretty much anything else cant get past his armor

My tip on killing this boss is by getting 3 high level reapers and a yuty it is a powerful combo because of the damage and resistance

the bear is like a golem so use a velonasaur.

This boss has 300k health and has armor as tough as rock elementals so your best choice for taking him out are Gigas once killed it'll drop high quality loot

To summon it go to a cave around 77 30 in jotunheim and there will be a terminal where you can pay the required 30 runestones to summon

About 8 lvl 140-150 wild tamed gigas should do the trick

The hardest one of the worldbosses (imo) had crazy damage resistance when I fought it and had 300k health