Windigos are spirits meant to punish the hateful by freezing them, thus preventing them from perpetuating hostilities. They serve as a reminder to ponies that their cumulative emotional state affects the climate and balance of the entire world.
They naturally exude a Penance Aura, allowing them to create Hoarfrost from hatred. They are also able to shape-shift, as displayed by Melancholia. The extent of this ability apparently extends only to pony forms.
According to Melancholia, they are able to perceive The Never, but cannot travel there.
- Hysteria was the Windigo contacted by Princess Luna. The interaction is viewed through the chained memory Lozenge found in the ruins of Canterlot. By the Fourth Era, she is presumably in the TRAK with the other windidgos, though her fate is never explicitly revealed.
- Parasomnia is the narrator and protagonist/antagonist of Source: Armiger.