Felix is one of the two main protagonists of All That Remains along with his big sister, Shayle. He ran away from home with her and was told that his father was taken prisoner by the Remnant for unclear reasons.
Like his sister, Felix was born in the village of Zeza, a Zebra Remnant controlled town in the South of Equestria. Never sharing his sister's love and longing for the Pre-War world, Felix focussed on more practical and current interests.
While his sister was forced to stay at home all day at the order of their father, Felix was allowed to go to class and learn whatever the Remnant thought fit to teach the youth under their influence. While early on Felix talked about learning history with his sister, in more recent years the young colt was taught about skills necessary to survive and thrive in the Wasteland of Equestria.
He exhibits at least rudimentary knowledge of medical supplies and practice, as well as some understanding of technology and how to hack terminals. Despite his practical knowledge, Felix still carries around books and has an almost endless need to learn more, no matter how insignificant something may seem.
Before leaving home, he was dragged from bed by his sister's frantic packing up of their belongings. Too tired to argue, he willingly left with her and ran into the Wasteland, only being told that his father was a prisoner and if they didn't leave they could join him.
A list of Felixs perks can be found here.