Great Grey Wolf Sif

According to lore, Sif was Artorias the Abysswalker's partner. When Artorias was swallowed by the Abyss, he threw up his Greatshield to protect Sif, as he could no longer bear it with his arm broken. Now, Sif guards their fallen comrade's grave and his ring, to ensure that what happened to Artorias, doesn't happen to anyone else.