This page contains information regarding Star Trek: Prodigy, and thus may contain spoilers.
Zero was captured by The Diviner at the Tars Lamora prison colony, where other slaves were forced to look upon the Medusan unprotected to brainwash them. Zero managed to escape and fashion a makeshift containment suit for themselves to safely interact with corporeal lifeforms. They became a rebel fighter known as "Fugitive Zero". In 2383, Zero helped fellow prisoner Dal R'El take possession of the recently-discovered USS Protostar.
As a Medusan, Zero possessed telepathic powers, often stating what others were thinking with or without their permission. They also had their species' natural aptitude for navigation, though until they found the Protostar they had never piloted a starship before. Like other Medusans, Zero was an energy-based non-corporeal lifeform. Without a body, they identified as genderless. (PRO: "Lost and Found")