Cavis
From Tardis Wiki, the free Doctor Who reference
Cavis and her partner Gandar are Gallifreyan Interventionist Agents (CIA), recruited from the Patrexes College and totally loyal to President Romana.
She had been on over 30 missions without regenerating and therefore only had one heart. She also had messy blond hair.
She was decapitated and failed to regenerate. (EDA: The Shadows of Avalon)