Decapod

Decapods are a sapient species of giant land-based cephalopod-like creatures from the planet Mars.

Biology
Decapods are cephalopod-like beings, standing about 40 to 50 ft tall (~ 12 to 15 m), with ten tentacular limbs, of which five are employed as arms and five as legs. They have three lidless eyes and a round rubbery small mouth with no teeth. The leg-tentacles end in padded feet-like extremities, while the arm-tentacles (furled when not in use) terminate in hand-like appendages, each equipped with ten digits, two of which are thumbs. Unlike Earth octopuses, their tentacles are smooth, without suction cups. Their skin is leathery and hairless, black on the males and chocolate-brown on the females.

Decapods live on land, but enjoy swimming, and are speculated to have evolved from aquatic ancestors. They communicate in bird-like sounds and can release soporific orange gas from their mouths. Some of their vocalizations are too high for Humans to hear. Likewise, Human speech is too low to be audible for the Decapods. Their habits are diurnal, being active during the day and asleep at night.

Culture and society
Their technology is advanced, including interplanetary ships and nearly transparent bulletproof armor. They habitually keep members of other species as pets.

Appearances

 * "The Human Pets of Mars", by Leslie F. Stone (1936)