25. Lizzie Samuels
How children have been affected by growing up surrounded by zombies – it's an intriguing theme that's run throughout this series. This world has clearly damaged Rick’s son Carl, as well as countless other youngsters who've popped up briefly over on the show. But no one’s been sickened as much as Brighton Sharbino's Lizzie, an adolescent girl so confused about life and death that she gave walkers names ... and then murdered her own sister in order to prove that being undead isn't so bad. More terrifying than any zombie, this kid was a sweet-faced, sharp-fanged rebuke to any hope that the rising generation might make the future brighter.