It is assumed that Mr. Gilbert spent most of his life living in Atlanta. It is possible that he was a religious man, as he can be seen wearing a cross necklace in "Vatos". He is now an elderly man who lives in a nursing home and is being taken care of by the nurses and Felipe. He also spends time with the nursing home's other residents such as Abuela. When the outbreak occurred, the nursing home staff abandon him and other residents, leaving them in the care of Felipe, Guillermo, and the other Vatos gang members.
While Rick Grimes, T-Dog, and Daryl Dixon stand-off in a confrontation with Guillermo and his men over Miguel, Glenn Rhee, and the bag of guns, Abuela rushes out in search for Felipe, worried for Mr. Gilbert, who needs his inhaler. He has began to suffer an asthma attack.
Rick follows Felipe and Abuela to the nursing home where he sees the elderly being cared for and sees a group of people trying to comfort Mr. Gilbert and help him with his breathing. The old man receives an inhaler and recovers from his asthma attack.
- Killed By
- Unknown Cause
At some point, everyone at the nursing home was killed.
Although it is not known how Mr. Gilbert died, in a deleted scene for "What Lies Ahead", Rick's group returns to the nursing home to find all of the Vatos dead due to another unknown group of people having executed them and walkers invading the nursing home afterwards. It's possible that this event still happened (sans Rick's group returning after the CDC explosion).
This list shows the victims Mr. Gilbert has killed:
- Possibly a few zombies
- "Vatos" (No Lines)
- Mr. Gilbert is one of five characters known to have asthma.