Spiky is a yōkai who briefly appears in the series.
Spiky resembles a porcupine with black quills. It has grey skin and red eyes. It also has a small patch of dull yellow fur bangs.
Spiky is a shy yōkai and hesitates to mingle or open up to others. Its reserved attitude is because of its fear of humans. Eventually, Hanae comforts Spiky with a small pep talk, which made it more courageous and willing to get exorcised.
Spiky has the ability to cause tremors in his surroundings but most likely that occurs whenever it is exasperated or afraid. Black ink splotches appear on the walls when Spiky travels to another room quickly (seen in the episode "The Marked Difference").
- Being a shy yōkai, Spiky quickly befriends Fuzzy before it leaves for the Underworld.