Spoiler warning: Plot and/or ending details follow.
Linus was a Saurian man, a Starfleet officer aboard the USS Discovery in 2257. He served in the sciences division and held the rank of lieutenant junior grade. He was ill when Christopher Pike came aboard to take command of Discovery and sneezed on Evan Connolly as he, Michael Burnham, Saru, Pike and Nhan rode together in a turbolift. (DSC episode: "Brother")