Pike's former yeoman, presumed dead on Rigel VII, who survived to become the planet's tyrant.
Zac Nguyen was a yeoman under Christopher Pike who was lost and presumed dead during an earlier, failed Enterprise mission to Rigel VII. He was played by David Huynh.
When the Enterprise returned, Pike discovered that Nguyen had survived and made himself a despotic ruler. Radiation from surrounding asteroids erased people's memories, but Nguyen and his guards were protected inside his castle, letting him rule laborers who forgot everything each night. Pike fought his way into the castle and defeated him, and the crew restored the laborers' memories.