In 2244, Straal and his research partner Paul Stamets discovered a mycelial network, based on Prototaxites stellaviatori, that spanned the universe and could be harnessed for rapid travel across vast distances. The two openly talked about the possibility of receiving the Zee-Magnees Prize when their research was completed. (DIS: "Context Is for Kings")
While Stamets considered the possibility of an organic mycelial harvest based on terraforming, Straal quashed the research because he wanted to keep the crop captive. (DIS: "The War Without, The War Within")
When war broke out with the Klingons in 2256, Starfleet separated Straal and Stamets, and pressed them into service, developing a practical propulsion system based on their findings. Straal was assigned to lead the team on the USS Glenn.
Six months into the project, Straal communicated to Stamets that he had made a breakthrough in the drive that allowed them to make far greater displacements than before, though Stamets was concerned that the process was unsafe. Shortly after, Straal and the rest of the Glenn's crew died of helical trauma when the ship hit a Hawking radiation firewall while exiting the mycelial plane. Stamets participated in the away team that boarded the Glenn and discovered Straal's remains. (DIS: "Context Is for Kings")
Straal was played by Saad Siddiqui.
He also briefly appears in Star Trek Online.