Fossil, nicknamed "the Old Lady" by the Resistance's bomber personnel, was a Martigrade of female gender. She held the position of commanding officer for the Resistance's StarFortress unit which encompassed both Cobalt and Crimson Squadron. After the D'Qar evacuation, she found herself on the Raddus as extra personnel, deeply saddened by the Resistance's defeats. At a later point, she gifted a Resistance ring to Rose Tico.