Jack the Ripper is a minor villain from the first arc of JoJo's Bizarre Adventure, Phantom Blood. He is based on the famous historical assassin.
Jack used the guise of a nobleman to lure women, after which he killed them. Dio Brando encounters him and turns Jack into one of his zombie underlings. After this Jack turns into an abominable monster, feeding on corpses given to him by Dio. The group of Jonathan Joestar, Will Zeppeli and Speedwagon is attacked by Jack inside the tunnel entrance to the Windknights village, using various scalpels buried into his body to attack. After Will deflects the scapels with his Wine Cutter, Jack opens a secret passage on the tunnel and enters it. Will gives JoJo a glass of wine and tells him to defeat Jack. Jack takes advantage of the darkness and attacks by using a huge torture device, but JoJo learns to use the wine to track down Jack, attacking him from behind a wall and disintegrating him.