Triped

Tripeds are a sapient, spacefaring alien race and part of a peaceful multi-species interstellar society. Physically, they are notable for their trilateral symmetry. Their planet revolves around a star located in the Aquarius constellation, but not visible from Earth.

Biology
Tripeds have a trilateral symmetry with no front or back side, which enables them to quickly change direction without turning. They have three evenly-spaced arms, three evenly-spaced legs, six evenly-spaced eyes, and a breathing orifice on top. Their three mouths are vertical gashes located between each arm and the next. They stand about 4 ft in height (~ 1.21 m) and have dark shiny blue-grey skin. Their six eyes are round, oyster-grey with round black pupils and eyelids, and can all focus independently or in pairs. Their hands have five digits, four of which mutually opposable (i.e. "one finger, four thumbs"), and the feet bear some resemblance to a chicken's. The brain is located within the upper torso, which expands and contracts as they breathe. A frill of curved spines on their necks acts as hearing organs. They have no vocal cords, but a tympanic membrane under their mouths which allow them to speak verbally. Since their mouths aren't connected to the respiratory system, their speech would be more accurrately described as belching.

Tripeds are naturally herbivorous, and need a breathing apparatus to survive on Earth, as the atmospheric composition of their homeworld is different. They can survive by consuming Earth food, but not indeffinitely, as they require additional nutrients that are not present in Earth's plant life. Like many species, they also require sleep.

Appearances

 * "Rule Golden", by Damon Knight (1954)