Aspect of the Dragon Mother
Aspect of the Dragon Mother has 1,500 health.
It takes extra damage from fire; frost and spirit do nothing to it at all. Blunt, slash and pierce land at full damage, so that is what to bring.
Nothing but a player can damage it, so tames, Dvergr and summoned companions do nothing for this part of the fight.
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.
Aspect of the Dragon Mother is a phantom copy of 
Moder that 
Kall Fimbulbringer summons during his second phase. At 1,500 health it is the least durable of the seven aspects and the only one that flies. It is immune to frost and spirit damage and weak to fire, so its own element is useless against it while the opposite one works, and it runs at 6. Player attacks are the only thing that damages it.
Weak to fire, immune to frost and to spirit. That inverts the usual Deep North loadout: a Frostfire weapon loses its frost half entirely here and only the fire half counts. Its cold breath is 180 frost in a sustained cone, the single biggest elemental hit any aspect has, so break line of sight rather than trying to tank it.
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