Eli

Eli was a boy who encountered Big Boss in 1984. During this time, he entered a physical struggle with Big Boss and pinned the latter behind a chair. Eli then withdrew a knife and attempted to stab him, only for his older opponent to parry the blow and knock him to the ground, disarming the boy and threatening him with his own knife. He would later chase Big Boss while commandeering a Metal Gear in Skull Face's possession.

Behind the scenes
Eli made his debut appearance in the E3 2013 trailer for Metal Gear Solid V: The Phantom Pain. In the trailer, he is described as "A Youth who Curses his Fate." He also appeared in the E3 2014 trailer, showing him struggling with Big Boss. In this instance, the back of his jacket featured the words "Never Be Game Over," along with the Japanese characters 液体人, roughly translating to "Liquid Man." His appearance in the E3 2015 trailer shows him jumping into the Metal Gear Skull Face leads Big Boss to, subsequently using it to chase Big Boss. He is also shown sitting next to a similar looking boy in a helicopter when Big Boss is heard saying "Les Enfants Terribles, Zero called it."

Eli's age, appearance, character description, and jacket decoration in The Phantom Pain trailers has led to speculation that he is a young Liquid Snake. When asked about Eli's design in an interview with Game Informer, during the lead-up to Ground Zeroes, Yoji Shinkawa said he was forbidden to answer at that moment. This connection to Liquid is further alluded in the E3 2015 trailer.