Shou Tucker

Shou Tucker, the Sewing-Life Alchemist, was referred to Edward Elric by Colonel Roy Mustang in Chapter 5 when the Fullmetal Alchemist was in need of a bio-alchemist whose research notes might hold a clue to restoring his and Alphonse's bodies. Tucker had gained a bit of notoriety and earned his State Alchemist's License two years prior to the series by producing a chimera capable of human speech. Ed and Al begin visiting Tucker at his estate to pore over his library of texts and forge a bit of a friendly relationship with the Sewing-Life Alchemist as well as his young daughter Nina and their dog Alexander, though Tucker's wife was said to have left the family two years before. Tucker explains to the Elrics that bio-alchemy, especially in the field of chimeric research is experimental at best and results in a large number of failures and false starts. Tucker himself notes that, ever since the speaking chimera that earned him his license, he has yet to present an alchemical breakthrough worthy of his yearly State Alchemist assessment and fears that a failure this year will lose him his certification and research privileges.

When Tucker reveals to the Elric brothers that he has finally managed to create another speaking chimera, Edward quickly perceives that Tucker has bypassed the impediments of artificially creating a being capable of comprehending and vocalizing speech by instead alchemically merging a live human with an animal - in this case Nina and Alexander and in the previous case, his wife. Tucker coldly confirms Edward's gruesome suspicions, to which Edward responds violently. The Sewing-Life Alchemist taunts Fullmetal between blows, stating that the two alchemists are alike in their sacrilege - that Edward's attempt to steal his mother's life back from the grave and Tucker's use of his family's lives to further his research are both indicative of scientific minds that seek knowledge despite any preconceived taboos attached.

In the manga
Unable to reverse the damage that Tucker has done to Nina, the Elrics have no choice but to leave the estate and report the incident to Colonel Mustang, who places Sewing-Life under house arrest with his daughter until he is to be tried in Central City. But before Lieutenant Colonel Maes Hughes and Major Alex Louis Armstrong arrive in East City to take him into custody, the mysterious Scar makes his first appearance by breaking into the estate and murdering Shou Tucker.

Tucker later reappears in a dream in Chapter 43, accusing Edward of turning his brother and mother into monsters.

2003 anime
Though in the manga the Elrics meet Shou Tucker as part of the normal chronology, in the 2003 anime series the Tucker arc is a flashback set while the brothers are preparing for the State Alchemy exam and Tucker himself plays a significantly larger role in the anime's storyline.

Instead of being another alchemist under the jurisdiction of Colonel Mustang in East City, Tucker is under the command of Brigadier General Basque Grand in Central, who continually pressures the Sewing-Life Alchemist to perform in accordance with the high standards set by his first chimera. After Edward's confrontation with Tucker, Grand immediately steps in to take the Tuckers into custody and orders the Elrics not to speak the truth of the matter to anyone (suggesting that he had known the truth behind Tucker's chimera beforehand). Though Edward interferes to allow Nina to escape being a test subject in what Edward calls Grand's attempt to create a "half-beast army", Tucker remains in custody and is reportedly sentenced to death without a trial as part of a cover-up.

In actuality, Tucker was not executed but sent to Laboratory 5 as a researcher and test subject. In the 2003 anime's version of the Lab 5 arc, Edward encounters Tucker - who has now become a monstrous chimera himself - during his investigation of the deeper echelons of the facility. Since Nina was a chimera at the time of her death, Tucker had to use the law of equivalent exchange on himself, transfusing the canine influence out of Nina while leaving himself a hideous beast with the appearance of a man crucified upon the back of a humanoid dog. Tucker is shown to have created several more chimera and acts as their master. In cooperation with the Homunculi, he attempts to trick Edward into fashioning a Philosopher's Stone out of prison inmates, hoping that the Homunculi will help create new Homunculus body for Nina with his memories as the foundation of her new soul. Paranoid and very unstable, Tucker joined up with anyone who could offer him the protection needed to complete his goal. He joined with Greed's group briefly, most likely on the promise that he could give Greed the immortality that Greed desired, as well as serve as a doctor to the other chimera working with Greed.

After the demise of Greed and his followers, Shou accepted Frank Archer's offer to rejoin the military under his command with alacrity. Using his new-found military privileges in return for building an army of chimera for Archer and the Führer, Tucker used his research to create lifeless dolls in Nina's image by transmuting her remains. Learning that Al became a vessel for the Philosopher's Stone, he deceived the boy by offering to teach him how to master the Stone; in reality, he only wanted to use Al to transmute a fully-human Nina from his chimera-dolls. Though Tucker succeeded in the first flawless Human Transmutation, Sloth pointed out that Tucker's will was not strong enough to bind Nina's soul into the new body made for her. This bit of information drove Tucker further mad with his hopes shattered. Tucker was last seen drawing alchemy arrays on a wall with the Nina doll in his arms, either bent on bringing his daughter back or trying to relive the happy times before his daughter became a victim of his research.

Trivia

 * In the original Japanese, Tucker's first name is pronounced as "Show", while in the English dub, it's "Shao".
 * Tucker is arguably the most widely hated character in the series, both by fans and characters.
 * In Hiromu Arakawa's "In Memoriam" omakes, Tucker is the only one shown going to Hell instead of Heaven, with not even truly heartless characters like Envy, Solf J. Kimblee, Lust or Barry the Chopper joining him.