Grand Fisher

is a Hollow that had evaded Shinigami for 54 years and is responsible for the death of Ichigo Kurosaki's mother, Masaki.

Appearance
In his Hollow form, he 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.

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.

History
The Grand Fisher has eluded the Shinigami for 54 years, and Soul Society has an extensive database on this highly infamous Hollow. Six years before the main story, the Grand Fisher was hiding by a swollen river in Karakura Town. Its body was hidden, and the lure had taken the form of a young girl. Ichigo and his mother, who were returning from Ichigo's karate dojo, passed by Grand Fisher, and Ichigo noticed the lure on the river bank. Ichigo thought that she was about to jump in, and ran to stop her. Masaki tried to stop her son, but was killed by the Grand Fisher.

Agent of the Shinigami arc
When Ichigo and his family visit the grave of Masaki, Ichigo sees the Grand Fisher's lure, which is in the form of the girl he saw on the night of Masaki's death. He runs towards the lure, but it vanishes. Karin later sees the same girl and, realizing that it was not a living person, went to direct it to a nearby priest. When the Grand Fisher realizes that she can see and hear him, he pins her to the ground. When Yuzu tries to help her sister, Grand Fisher catches her with a tentacle and decides to eat her first as she is in his way. Ichigo, however, severs the tentacle and one of Grand Fishers hands, rescuing his sisters.

After recognizing the lure, Ichigo questions who she is. The lure's skin peels away, revealing its true appearance, and it reattaches itself to Grand Fisher. While the Grand Fisher wonders if all these people who can see him will fit inside his stomach, Rukia Kuchiki explains who the Hollow is and how he traps his victims. Enraged, Ichigo attacks the Grand Fisher, who dodges and regenerates his severed hand. As the Hollow attacks Ichigo, Rukia tries to attack it with Kidō, but Ichigo tells her to stop, insisting that it is his fight.

As the fight continues, Grand Fisher gains the upper hand, managing to stop Ichigo's blade with his bare hand. The Hollow pierces Ichigo with spikes that grow out of its fingers, searching his memories. Grand Fisher then has his lure take the form of Ichigo's mother, using her as a shield to prevent Ichigo attacking him. Grand Fisher punches through the lure, severely injuring Ichigo, but Ichigo grabs his arm and stabs the Hollow back, inflicting enormous damage on him. The Grand Fisher then jumps into the body of the lure and escapes, with Ichigo unable to follow.

After his defeat by Ichigo, Grand Fisher returns to Hueco Mundo, where he is seen being patched up by the Arrancar Iceringer, while another Arrancar Di Roy Linker scolds him for running away from a Shinigami before even using all of his strength. Iceringer the shatters his mask and turns Grand Fisher into an imperfect Arrancar.

Arrancar arc
When the Grand Fisher is about to attack Kon in Ichigo's body the talisman Isshin gave Ichigo is thrown in between the two creating a barrier in between them. Isshin then appears dressed as a Shinigami and berates Ichigo for not wearing the talisman although he told him to where-ever he went. He then addresses the Grand Fisher as "Mr. Hollow" and says that Ichigo is not home and suggest that he "plays" with him instead When the Grand Fisher questions who he might be, Isshin apologize and introduce himself. Hearing the name Kurosaki, the Grand Fisher realizes that Isshin is the father of Ichigo and Isshin confirms this.

When the Grand Fisher realizes that Ichigo is the son of a Shinigami and therefore the real thing, he notes how he finally understands how he lost to him. He also states that he has no interest in Isshin and that he only came to kill Ichigo and orders Isshin to hand him over. Isshin, however, reveals that he does not know where Ichigo is because Ichigo is no longer a kid. He then explains that even if the Grand Fisher has no interest in him, he himself came to kill the Grand Fisher.

The Grand Fisher only begins to laugh and questions if they believe that he is nothing but a regular Hollow and transforms, growing in stature. A shocked Kon says that he is larger than a Menos Grande, which Grand Fisher takes as an insult. Isshin reveals that he is an Arrancar, a Hollow who had removed his mask to gain Shinigami powers. The Grand Fisher draws his Zanpakutō, saying that the size of a sword shows the amount of power someone may have and says that Isshin cannot win with his twig sized sword. Isshin smiles and challenges the Grand Fisher to give it a try and draws his own Zanpakutō and the two clash. He kills the Arrancar with a single cut from his sword.

Isshin states that all captain-level Shinigami know how to compress their Zanpakutō; otherwise all captains of the Soul Society would be swinging around swords the size of skyscrapers much like the Grand Fisher was doing and tell him to remember; never to judge an opponent by the size of their Zanpakutō. He then calls him a kid and says that he should not talk about a Shinigami's strength until he could understand that.

Hollow Form
Spiritual Power: Grand Fisher possesses enough spiritual power to fight Ichigo with ease, blocking his Zanpakutō with his hand and inflicting severe injuries on him.

Limb and hair growth: Grand Fisher displays the ability to extend his limbs and fur in order to attack, impede or restrain an opponent.

Tentacles: The Grand Fisher has tentacles, which he uses to capture and restrain Yuzu. They come from inside the holes in his mask underneath his eyes.

Lure: Grand Fisher typically hides his body and uses a lure that protrudes from his neck to attract potential victims. It can also be transformed into a decoy copy of someone close to his enemy's heart, allowing him to keep the enemy from attacking, as they will be unwilling to harm the decoy. The lure can be disconnected from the main body.

Memory probe: Using extensions hidden inside the fingers of one of his claws, Grand Fisher can pierce an opponent's body and look into their memories, searching for something that the enemy cannot cut. Then, with the other hand, he transforms his lure into that something.

Second body: The lure also functions as a second body for Grand Fisher. Grand Fisher states that both the lure and himself are his real body and when one is injured, it can jump into the other body.

Regeneration: He has shown the ability to regenerate at a somewhat high speed. When his hand is cut off by Ichigo, Grand Fisher's fur covers the injury and takes the form of the missing appendage. A new hand then emerges from the fur. He only exhibits this ability in his original Hollow form.

Arrancar Form
Transformation: The Grand Fisher demonstrates the ability to change his form when confronting Isshin. He grows greatly in size, with horns jutting out from his shoulders. He describes this as his true strength.

Zanpakutō: Grand Fisher has a Zanpakutō about the size of a two-story building with a rectangular tsuba. He did not try to release it and he was killed shortly after drawing it. It is unknown if this imperfect Arrancar had a Resurrección.

Appearances in Other Media
Grand Fisher is an unlockable character in Bleach: Dark Souls, in his Hollow form. One of the strongest characters in the game, his very powerful Hair Extension attack could cover 3 other opponents and slicing their health gauge in half or more.

Trivia

 * In the anime, he prefers to eat women, which is why he killed Ichigo's mother; in the manga, he prefers to eat children, and Ichigo's mother merely got in the way.