Jack the Ripper

Jack the Ripper (切り裂きジャック) is an antagonist featured in Part I: Phantom Blood. He was inspired by the historical figure

Personality
Jack the Ripper is shown to have a gentlemanly facade, able to convince a woman to walk with him on a dark night. When he reveals his true colors, he does not hesitate to stab the unarmed woman to death. As a vampire, this trait becomes even worse, as he becomes even more cruel and insane. Jack is shown to have a desire only to cut things and cause pain.

Phantom Blood
Jack the Ripper, after killing what was presumably his last real victim, was selected by a then-incapacitated Dio Brando to become one of his vampire minions. Refusing at first, Jack attacked Dio, but after seeing this had no effect, Jack accepted Dio's offer. (In the anime, Dio instead hypnotizes Jack to come forward so that the former could suck his blood to turn him into a loyal zombie servant.)

Later, he corners Jonathan Joestar, Robert Edward O. Speedwagon and Will Anthonio Zeppeli in a tunnel, killing their horses and hiding inside the body of one. He is eventually injured by Zeppeli with his Ripple attack, but escapes into the labyrinth, intending to attack from the darkness. Jonathan Joestar, now learning to better control the Ripple, is tasked by Zeppeli with killing Jack without spilling a single drop of wine from the glass Zeppeli gives him. Using the liquid to pinpoint Jack's location on the other side of a wall, Jojo eliminates Jack with a huge Ripple burst, ripping through the brick wall and succeeding in the task assigned to him by Zeppeli.

Abilities
After being turned into a zombie, Jack becomes even more insane than he was as a human. Incapable of feeling pain in his undead state, Jack uses this to his advantage - inserting sub-dermal scalpels all over his body. Jack also has incredible speed, demonstrated by his being able to kill a man, decapitate two horses, and hide inside the body of one in a matter of seconds.

Scalpel: With the scalpels buried in his body, Jack is able to expel them merely via muscle contraction. He then throws these knifes with pinpoint accuracy over great distances. Monstrous Knife: Re-modeled from a Dark Ages torture instrument, Jack uses the knife to cut his foes to shreds.

JoJo's Bizarre Adventure: Phantom Blood (PS2 Game)
Jack appears as a boss fight in two chapters. In the first one the player must defeat him using Zeppeli as the battle has a time limit.

In the second battle, the player takes control of Jonathan, as Jack keeps runing around the stage, trying to make surprise attacks with his torture instrument. Since Jonathan learned the hamon up to this battle, a small glass of wine appears on the screen's coner, every time Jack tries to appear near Jonathan the glass of wine starts shaking, indicating his presence.

Jack can be played on some battles on EXTRA MODE. His special move allows him to launch all the scalpels in his body to attack the opponent.

Jojo's Bizarre Adventure: Stardust Shooters (ANDROID/iOS Game)
Jack appears as one of the several PART I characters who possesses a metal striker. His FINISH Move has him using the torture device on the defeated opponent. If defeated, Jack's metal striker will drop a knife, if any other metal stiker gets near it, they'll lose some health points