Frankensteiny

Frankensteiny (フランケンシユタイニー, Furankenshiyutaini) is the second guardian ghost of Faust and is also his dead pet dog.

About
Frankenstieny is the pet dog of Faust and Eliza Faust, who was with them ever since their marriage. Whilst never mentioned specifically, the dog apparently died at some point in the past. It has ever since been with Faust in its skeleton form, constantly wandering with him. It made its first debut during the 1st round of the Shaman Fights where it was following Faust around. Later when Faust was attacked by the Icemen and they destroyed his wheelchair, he revealed that he used the bones of Frankensteiny as replacement for his missing legs, and that it can be completely revived with a little amount of Furyoku and give Faust great jumping power.

O.S. Frankensteiny
O.S. Frankensteiny

Description: After giving up his lower legs to Eliza, Faust was confined to a wheelchair and became unable to walk for the rest of his life. However after training with Kyōyama Anna he learned how to Over Soul the bones of his dead dog into a pair of legs.
 * Shaman:Johann George Faust VIII
 * O.S. Type: Spirit Type
 * Spirit Ally: Frankensteiny
 * Medium Used: Skeleton Remains of Frankensteiny

This is done by splitting the bones up in the middle of the spine, so that the front legs are attached to his left leg and the back legs are attached to his right leg, both of them being attached with the spine. When first shown this seemed to put some restrain on the bones, but has not been addressed since.

Anime/Manga Difference
In the anime, Faust never loses his legs to Eliza, and Frankensteiny is never seen walking around, so therefore is he only seen briefly in a flashback in Episode 15.

Trivia

 * His name is play of the name Frankenstein, a mad doctor who stitched together corpses and reanimated them with the power of lightning.
 * Frankensteiny is a Manchester Terrier.