Aspect of the Dragon Mother
Boss
What to know
Aspect of the Dragon Mother has 1,500 health.
It takes extra damage from fire; frost, spirit and nonplayer do nothing to it at all. Blunt, slash and pierce land at full damage, so that is what to bring.
Its hardest hit is dragon coldbreath at 180 frost, out of 5 attacks.
Some of what it throws is elemental, so frost resistance is worth having.
Of everything craftable, 
Thunderblood Crossbow, 
Lightning Strike and 
Staff of Embers put the most damage through what it resists.
Spawn command
With devcommands enabled, this spawns Aspect of the Dragon Mother in front of you. The third number is the level: 3 spawns a 2-star.
Creature ID: Aspect_Moder · all console commands and IDs