Castan

Castans are a species of octopus-esque aliens from the aquatic planet of Castor VI.

Physical
Bearing some resemblance to humans in size and shape, the similarities end starting with their head: specifically the presence of anywhere between 4 and 12 tentacles that take the place of hair. Despite their location, these tentacles are extremely prehensile and strong, and can easily catch a person off guard, as a skilled Castan can use each tentacle to wield a weapon, carry large objects, and/or aid in movement. In addition to these tentacles, Castans have an ink defense mechanism similar to octopuses and squids in the water. However on land, this ink serves more as a dry smoke-screen. That being said, Castans can survive and breathe on both land and in water, however their skin is susceptible to drying out. The final similarity to cephalapods comes in the form of their lack of endoskeleton, instead relying on strong muscle tissue to maintain shape and stand upright. However this does permit an almost insane level of flexibility.

Trivia

 * Castans are based off of Amelia's original concept species.