Jase Zero (born Calvin Nickels) was a Human male and leader of the Human Extinction League.
In 2020, Zero and the HEL held Tera O'Herlihy in order to force her father, Marcus O'Herlihy, to sabotage the USS Lewis & Clark's mission to Saturn. Marcus was unsuccessful and Zero was stunned by a blast from the USS Enterprise's phasers and then taken into custody by the authorities. (TOS novel: The Rings of Time)