Allen is a survivor of the zombie apocalypse and an antagonist in AMC's The Walking Dead. Is also a survivor of the group of Tyreese, trying to find a safe haven with his wife, Donna, his son, Ben, and Tyreese's sister, Sasha. Allen first appeared in the mid-season finale of Season 3, "Made to Suffer". He is the tertiary antagonist of the second half of Season 3.
Allen was originally a member of Tyreese's group, along with his wife, Donna, and his son, Ben. After Rick kicks their group out of the prison, shortly after his wife's death, he and his group joins Woodbury, where The Governor tells him that they're fighting against the Prison group, and lies to him by saying that they provoked them into it. Allen becomes a strict member of the Governor's army after his son is accidentally shot by Merle Dixon. He joins the army on an attempted prison assault, but it is failed when they are flashbanged and shot at (killing no one in the process.) Once the army escapes own the road, the army begins to revolt against the governor in fear of their lives about going back. Allen yells at the opposing crowd along with The Governor yelling about how they killed his boy, showing he wants to avenge him. After the governor slaughters the entire army, Allen is left alive, pointing his rifle at The Governor. However, The Governor leads him into a false sense of security by not aiming his gun, before quickly shooting him in the head with his pistol, instantly killing Allen.
Allen is possibly the most unlike his comic counterpart psychologically:
- In the comics, Allen was a close friend to Rick. In the TV series, he has a more antagonist role and plotted to throw Rick out of the prison and kill the other group members, and eventually joined the Woodbury army. Allen didn't live long enough to find out about Woodbury in the comics, and never tried to kill anyone, unlike his TV counterpart who not only tried to kill the prison group members, but also The Governor.
- Allen has two sons in the comics, Ben and Billy. In the TV series, only one is seen, Ben.
- Allen never witnessed the deaths of his sons in the comics. In the TV series, Ben died before Allen.
- Allen and Tyreese seemed to get along in the comics, yet Allen is very hostile towards Tyreese in the show.
- In the comics, Allen's leg was amputated by Rick after being bitten. In the TV series, Hershel is the one to lose his leg in a very similar fashion (despite not dying from infection, unlike Allen).