18. Gareth
Gareth, the leader of the cannibals of Terminus, wasn’t always a horrible person. In flashbacks that told the story of what happened at Terminus, it seemed that in the beginning, Gareth was pretty mild-mannered and easygoing. But after Terminus was taken over by some pretty violent and sadistic people who tortured Gareth and the other survivors there, he changed into the monster he was by the time that he captured Rick and the others.
At that point, he and the others at Terminus were luring people into Terminus and then killing them to be butchered and eaten by the people there. They did grow some vegetables and fruit but their primary source of protein was eating the flesh of people that they had killed. Rick and the others were barely saved from becoming dinner for the people of Terminus by Carol’s assault on Terminus.
After the group managed to get away and they took refuge in Father Gabriel’s church, Gareth and the few survivors from Terminus pursued them. Gareth showed that he had no humanity left to redeem when he taunted Bob Stookey and ate pieces of Bob’s leg right in front of Bob. He explained to Bob that the people of Terminus did what they needed to do to survive by turning to cannibalism. But it was clear from how much Gareth enjoyed eating human flesh and enjoyed the torment he put Bob through that he was completely stripped of all humanity and would never be able to be redeemed.
So it was immensely satisfying when Rick and the others tricked Garth and his crew and surrounded them when they attacked the group in the church. Gareth started begging for his life after his fingers were shot off, but Rick butchered the butcher with his red-handled machete. Some people just can’t be redeemed in The Walking Dead world.