Grand Fisher

In his Hollow form, Grand Fisher resembles a giant hamster with bird-like hands and feet and a tentacle-like limb that hangs from his forehead, similar to the esca (lure) of an anglerfish. The lure is vaguely Human-sized and can be transformed to resemble anyone Grand Fisher wishes, usually taking the appearance of a young girl. It can act independently of Grand Fisher, and as long as either the lure or Grand Fisher himself survives, he cannot be purified.

Grand Fisher's first Arrancar

In his first Arrancar form, he resembles a smaller, more humanoid version of his old self with a tattooed face. His mask remnants consist of his entire lower jaw, which obscures half of his face.
When he appeared in the Human World again to kill Ichigo, however, his appearance changed drastically. His entire mask was left unbroken and the upper half sat on his forehead. He also had fur all over his body and was much larger. His Hollow hole was also higher than his previous appearance. He carries a large Zanpakutō on his back. These changes to his appearance have not been explained.