A visitor to Risa who speaks an unusually difficult language, intriguing Hoshi Sato; the two spend her shore leave learning each other's tongues and become lovers.
Ravis appears in the Enterprise episode Two Days and Two Nights, played by Rudolf Martin. He is a holidaymaker on Risa whose species and homeworld are unfamiliar to the humans.
Hoshi Sato has gone to Risa determined to practise new languages rather than relax. She overhears Ravis, whose speech proves so complex that the universal translator struggles with it, and asks him to teach her.
He in turn learns some English, and their lessons turn into a brief romance. Unlike the entanglements of her crewmates on the same shore leave, Hoshi's encounter is entirely happy, and she returns to Enterprise saying only that she made a new friend.