Before WKU: Cosby-Mosley spent his first two seasons at Wake Forest, where he appeared in three games. He saw action in one game during the 2025 season and played in two during the 2024 season.
HS/Misc.: Cosby-Mosley prepped at The Benjamin School in Florida, where he was a finalist for the Lou Groza Palm Beach County Player of the Year as a senior. He led his team to an 8-3 record that season, and recorded 122 tackles, four tackles for loss, three sacks, seven interceptions, three fumble recoveries and three forced fumbles during his high school career. Cosby-Mosley was a multi-sport athlete in high school, competing also in basketball in track and field. He was an FHSAA 1A state qualifier as a junior in both the 110-meter hurdles and the triple jump, placing fifth and 11th, respectively, in each event, and took the bronze in the triple jump as a sophomore with a personal-best jump of 44-10.25.
