Zorro

Zorro, like Robin Hood, was one of Astrolabus's past identities, as recited to the Sixth Doctor in his last incarnation. (COMIC: Voyager) In 1651, the Twelfth Doctor mockingly referred to the Knightmare as "Zorro". (TV: The Woman Who Lived)

Behind the scenes
Zorro is a famous fictional outlaw. He typically "signs" his defeated foes by slashing a "z" into their shirts.