Ecnalian

Ecnalians were a humanoid species native to the planet Ecnal.

Specifics
Ecnalian physiology had some aquatic characteristics, such as antenna, fins on their ears, webbed hands with four clawed fingers, and fins along the sides of each hand. However, they had belly buttons, Human-like feet with five toes, and facial hair.

Ecnalians developed a rare type of ground transportation: walking vehicles. Other technology included advanced scanners, various scientific equipment, laboratories and an observatory.

They were aware of intelligent life on other planets, such as the Lerows. Four musical performers and a juggler who visited an Ecnalian city were from distinctly different sentient species.

History
In 2266, Ecnalians were unable to stop a significant drain of the planet's life energy. From a walking vehicle, an Ecnalian leader and a pilot could see how animal life was struggling to survive. When James T. Kirk, Spock and Janice Rand beamed down to Ecnal, the leader asked if they could help solve the crisis. An investigation exposed the actions of a Lerow rocket. When communications were established, the Ecnalian demanded that the Lerows stop taking energy, but the ship's commander refused out of desperation. The landing party gave the Lerows a much-needed energy converter, and its crew departed gratefully. Afterwards, the Ecnalian leader invited Kirk, Spock and Rand to a banquet. Two female Ecnalian dancers entertained them after dinner.