Shinugami are familiar spirits that bond to sentient creatures as companions. Canine in form, they follow their masters without fail. Shinugami possess several forms depending on the creatures they imprint upon: Natural, Forest, Mountain, and Urban. In their Natural Form, they are wispy and incorporeal, lined with veins of ghostly energy. Their other forms are corporeal, though they retain the ability to levitate, and they can return to their Natural state at will. Once they imprint, they keep corporeal forms for life and cannot switch to another. Their forms affect which moves they can learn. Prior to humans' landing in Ultra Forest, the Urban morph did not exist, and it was only discovered when Shinugami imprinted on humans. Shinugami bred in captivity invariably take on Urban forms unless a tamed Kartana or Karasagei is also present. Forest and Mountain Shinugami can be captured from the wild, though doing so may enrage their wild master. The Urban form resembles the dog Pokémon found on Earth, while the other forms are more alien in appearance.
Shinugami are vengeful. Once bonded, they must be treated well, lest they turn on their masters and attack. Mistreating their master in any way provokes their anger as well. Shinugami are loyal to one person first and foremost, but will also serve a master's family, friends, and descendants. When respected, Shinugami make incredibly affectionate pets and intelligent guard dogs.