- "I was angry. My son was hurt, you were acting like it was his fault. I thought I was going to lose him. So... I wouldn't have been upset if you'd died. That sounds awful. No. What I mean to say is in the moment, as angry as I was... I just wasn't thinking straight. I get that way. Always had a temper."
- —Tammy to Maggie about overreacting to her son's injuries.[src]
Not much is known about Tammy's life before the apocalypse, except that she lived with her husband and son.
When Carl Grimes defended Sophia and himself from the bullies that previously attacked Brian because of his looks, Tammy immediately showed up at the infirmary, carrying her son and his friend's bodies on a blanket. She then threatened Carl and Maggie Greene, the leader of the Hilltop, along with her husband, Morton, saying that the boy should be locked up because of his attack. Although Carl insists it was an act of self-defense, Tammy keeps arguing with Maggie. She finally convinces her of giving Carl some sort of punishment. After that, Maggie sends her and her husband to their trailer.
She is then seen sitting on a dinner table inside the trailer with her husband and the Harlan family. They discuss Maggie's power, and how no one voted or had an opinion on her new occupation; implying that she just began to yell out orders. When they start thinking about a way of ending her "reckless" power, Gregory suggests they kill her.
Tammy is later seen at the infirmary, profaning and demanding where Maggie is. The latter appears in the medical facility, and Tammy complains that she saw Carl free. Maggie says that she will punish him but won't lock him up. Tammy replicates once again, and Maggie then threatens to relocate her, to which Claudette replies that she's lived in the Hilltop longer than her. Gregory intervenes and breaks up the fight, before he tells Tammy and the other parents to just calm down and take their boys home.
After the failed attempt on Maggie's life, Tammy explains to her about Gregory's plan and tried to warn her, but was still upset and angry because Carl nearly killed her son and apologizes to her for her temper. She and Morton later witnessed Gregory's hanging.
This list shows the victims Tammy has killed.
- Possibly numerous counts of zombies
Alpha disguises herself as one of Rick's people and infiltrates the fair grounds. Gradually, she begins luring people off the fairgrounds and decapitating them, then placing their heads on wooden pikes to mark the border between the land belonging to the Whisperers and Rick's communities, with Tammy being among them. She is later put down by Carl, Lydia, Dante or Andrea
- Each member of the Rose family was killed by a leader of different community.
- In Issue 140, Maggie calls Tammy "Claudette", most likely an error during publication.