A Brunali geneticist who engineered his son Icheb to carry a pathogen into the Borg Collective as a weapon.
Leucon is the father of Icheb, one of the Borg children on Voyager, introduced in Child's Play. When Voyager finds Icheb's home on a Brunali world repeatedly attacked by the Borg, Leucon and his wife Yifay welcome their son back, explaining that he was taken while visiting a new fertilization array, and Icheb chooses to stay.
Seven of Nine learns that Leucon lied about how Icheb was taken. He had engineered his son with a pathogen meant to infect the Borg, and placed him where they would assimilate him. Voyager rescues Icheb when Leucon sends him toward the Borg again.