Twolegged

Twolegged is an adjective used to describe an organism or entity that has two legs, i.e., a biped. It is used in biology, anatomy, anthropology, and everyday language to distinguish bipeds from quadrupeds or multipedal species. Although humans are the most familiar two-legged animals, many birds and some extinct species are also described as two-legged in various contexts. The term can apply to non-biological subjects, such as two-legged machines or furniture with two legs.

Etymology: formed from two + legged; modern standard spelling is two-legged with a hyphen; twolegged without a hyphen is seen in older texts, certain proper nouns, or in fictional settings. In some fantasy or fan communities, the term Twolegs is used as a specific label for humans, notably in the Warriors series, where Twolegs are depicted as non-native intruders and caretakers of the land.

Biological notes: Bipedalism is a locomotor strategy in which an organism moves on two limbs. It has evolved independently in different lineages and is a central feature of humans, enabling upright posture, freed forelimbs, and energy-efficient travel over long distances. In birds, two-legged locomotion accompanies other adaptations such as feathered bodies, hollow bones, and specialized joints. Some extinct species are believed to have walked bipeds while others used mixed gaits.

Use in culture: In fiction and speculative writing, "twolegged" can distinguish humanlike characters from four-legged beings, and in some franchises, the term Twolegs denotes humans.