Jeffrey Grimes (Comic Series)

Jefferey "Jeff" Grimes  is younger brother of Rick Grimes. He is also apparently the same age as Lori Grimes.

Pre-Apocalypse
Jeff still has not had an appearance (it is not been confirmed whether he ever will) and has only been mentioned twice, both times by Lori. Much about his past is unknown, aside from that he apparently broke an ankle while in elementary school. This event caused Rick to be beaten up by his peers, for attempting to stick up for Jeff. It was also revealed that he was Lori's best friend in high school, and was indirectly responsible for Lori meeting Rick and "hooking up".

After-Apocalypse
Nothing is revealed about Jeff's fate. It was hinted at that he may have had a crush on Lori, this is revealed while Lori is talking to Carl. She states that Jeff rarely came to visit after she and Rick were married.

Jeff's Fate
It is also unknown if he is dead, undead or alive, but given the lack of his appearance, things do not look good for Jeffery.

Rick Grimes
Rick is Jeff's older brother by two years. As a child, Jeffrey acquired a limp for a period because of some accident and Rick frequently fought with those who teased him in order to protect his younger brother.

Lori Grimes
Jeff and Lori were friends in high school. Jeff was the one who introduced Lori to Rick at a party. Other than that there is no relationship known about Lori and Jeff.

Carl Grimes
Carl remembers his uncle, but nothing more has been told of him by Carl. Carl is Rick's only son.