Thomas Richards

Thomas Richards is a character from the Walking Dead comic books series. He is one of the four criminals who were in the prison Rick Grimes and his group arrived in. During the time that the group spent in the prison, Thomas murdered Susie and Rachel Greene by decapitating them. When he was discovered to be the killer, he was locked up in a cell, but was released by Patricia, who thought he wasn't crazy and evil. He then attacked and attempted to kill Patricia, but was shot and killed by Maggie Greene. His body was then thrown into hoards of zombies, who tear the body apart. Thomas served as the primary antagonist of Volume 3: Safety Behind Bars.

Videogame
Will being taken to prison Lee Everett is told by a sheriff officer about when he took Thomas to prison. He was being sent for butchering his wife (as in the comics). The officer said that he kept screaming, kicking his seat, and yelling to his mother that he didn't do it, evening convincing himself. The officer said that he was one of the worst criminals he ever escorted.

The TV series
In the TV series, Thomas's counterpart's name is changed to Tomas and is a lot different in the show than in the comics. He is the leader of the five convicts in the prison who develops a hatred of Rick once he planned to take over the prison for his group. During a fight with the walkers, Big Tiny is deeply scratched by a walker, and Tomas kills him by ruthlessly bashing his head in. After that, Rick plans to kill Tomas, unaware that he has overheard his conversation with Daryl over it. During another run-in with the walkers, Tomas tries to kill Rick, but Rick makes it through his assassination attempts. Rick then squares off with Tomas, who tells him that the walkers were all over him and Rick says he knows and that "shit happens". After a few moments of silence, Rick slams his machete through Tomas' head, killing him. Tomas served as the primary antagonist of the episode "Sick" and overall the senary antagonist of the first half of Season 3.

Season 3

 * 3x01: "Seed" (No Lines)
 * 3x02: "Sick"

Trivia

 * is one of the darkest villains within The Walking Dead media, along with The Governor, Gareth, Martin, The Hunters, The Marauders, Owen and The Wolves, Troy, Alpha, Beta, William Carver, the Save-lot Bandits, and the St. John family (Andrew, Danny and Brenda).