Rojan, a male Kelvan in humanoid form.
The Kelvans are an intelligent and non-humanoid species from the planet Kelva in Andromeda Galaxy, where they control an Empire.
They were first encountered by the USS Enterprise in 2268, under the command of James T. Kirk, when a Kelvan advance squad scouted the Milky Way Galaxy in order to find habitable space, since the radiation level in the Andromeda Galaxy was rising. On the Enterprise they appeared in human form, so their true appearance is unknown. Brief mental contact between Spock and Kelinda resulted in a torrent of imagery flooding Spock's mind. Among this was a suggestion of "...immense beings...a hundred...limbs, like tentacles...minds of sufficient complexity that each limb was capable of performing a different function." Spock believed that this was the Kelvans' real form. Spock also learned that the Kelvans had given up most sensation and emotion, as unnecessary distractions. Their inability to adapt to these qualities of their humanoid forms proved their undoing. (TOS: "By Any Other Name")
In 2374, Lieutenant Commander Worf told Jadzia Dax that he had once fought Kelvans twice his size, yet he was unable to put young Kirayoshi O'Brien to sleep. (DS9: "Time's Orphan")