A mysterious being from Tau Alpha C who recognised Wesley Crusher's unusual gifts and later took him away as his student.
The Traveler first came aboard the Enterprise-D in Where No One Has Gone Before as the assistant to Kosinski, a Starfleet propulsion expert whose engine improvements were actually the Traveler's doing. His abilities flung the ship into a distant galaxy and then to a place where thought became reality. Exhausted, he helped bring the ship back.
He told Picard privately that Wesley Crusher had a gift that should be nurtured. In Remember Me he appeared to Wesley to help him rescue his mother, Beverly Crusher, from a warp bubble created in one of his experiments.
In Journey's End, disguised as Lakanta on Dorvan V, he helped Wesley, who had left Starfleet Academy, realise that his future lay elsewhere. Wesley left with him to explore other planes of existence, a path he continued in later appearances.