While JeoSeung Saja prefers to be known as he, that in no way restricts his physical form. The First Fox is a shapeshifter capable of taking on the form of a large silver fox or a hybrid or even fully humanoid form like his children. Unlike them, his humanoid and hybrid forms can look like anything he desires and he frequently uses this to change his body to suit him. It is for this reason that Foxes are the only Spirits capable of taking on a fully humanoid form with no animal characteristics.
JeoSeung Saja is the formal name for the First Fox, the leader of the Kumiho. This is a title, however, simply meaning Messenger of Death, and he is not the one who oversees the afterlife and the disposition of souls. It merely falls to him to decide when souls are bound for the rivers and when souls are allowed to return to their current life.
He oversees the ledgers of the living and dead, accounting for not only the living souls but also those of the dead who have not yet made it to The Three Rivers of Death. The names of the dead are recorded in red ink.