Rypdraugr

These creatures are nothing more than undead bodies encrusted in ice. This ice acts as a shield causing the body to be preserved and strengthened.
It feeds on the flesh of living creatures in order to provide replacement parts to body parts that are wounded. As it doesn't breathe it uses these parts as flesh to strengthen the body.
Many tales are spoken about those that venture out during the night's blizzards.  Travellers and children are ushered to never step out away from the warm fires kindle during the blizzard's howl for if one is foolish enough to step out their own soul will be pulled out from the wind.  For once the soul has left the body is encrusted in ice and frost and takes to moving in death.
It feeds on the flesh to heal and collects parts of the living or preserved dead in order to provide replacements to parts of its body that are wounded or broken.
It doesn't breathe it can withstand the most hostile of environments but is prone to rotting if it leaves the frost.
The ice is coated across the body working as a shield causing the body to be preserved and strengthened. The ice on the arms may be sharp or bulky working as either sword or mace.