Mika Samuels was a character first introduced in Season 4 of AMC's The Walking Dead. She was the daughter of Ryan and young sister of Lizzie. She portrayed by Kyla Kenedy.
Mika is the adopted daughter of Carol Peletier after her father is bit by a walker and put down. She counts to two with her when Carol is about to kill their father in mercy. She does seem intolerant with her sister's somewhat erratic behavior, calling her 'stupid' when Lizzie gets upset over the walker she'd named being put down. She is also somewhat wary of her sister's mental state, as she warns Carol soon after Carol becomes their guardian that something is just wrong with Lizzie.
Mika is shown to have some respect for her sister however, as she follows Lizzie's lead and proceeds to join the fight against the governor's militia instead of fleeing to the bus. When Lizzie and Mika are in the woods with Tyreese and baby Judith, Mika sometimes bickers with her sister, but also looks to her for reassurance when they're alone with walkers.
However, Lizzie, wanting to prove to Carol and Tyreese that walkers aren't different, murders Mika. Carol and Tyreese return to find Mika's corpse and Lizzie covered in blood. Moments after dying, Carol stabs her in the head to prevent reanimation.
Carol later kills Lizzie because she can no longer be around people.