Its legs freely stretch and contract. Using these springlike limbs, it bowls over foes with devastating kicks. After battle, it rubs down its tired legs.
(From Bulbapedia) Hitmonlee is a humanoid Pokémon with an ovoid body. Lacking a distinct neck and head, its upper torso has almond-shaped eyes with black rings around them and appears to lack a nose and mouth. Primarily brown, it has cream-colored, segmented arms and legs, with three fingers and three clawed toes respectively. The soles of its feet and its ankles have circular, yellow markings. It is an exclusively male species with no female counterpart.
Hitmonlee's legs freely contract and stretch similar to a coiled spring. This flexibility allows Hitmonlee to run with lengthy strides and gives it greater reach for its kicks. Its excellent sense of balance enables it to kick in succession from any position. After battling, it rubs down its legs to relax the tight muscles. Rare in the wild, it is primarily found in urban areas.
(From Bulbapedia) Hitmonlee may be a personification of taekwondo, a sport that focuses on kick attacks. Due to its lack of a head, Hitmonlee bears resemblance to mythical headless men such as the Xing Tian and the Hindu demon Kabandha. Based on its Japanese name and kicking attribute, Hitmonlee may also represent Japanese kickboxer Tadashi Sawamura. From the Japanese names of its Abilities—Flexible, Life-Risking and Acrobatics—Hitmonlee may also be based on an acrobat.
(From Bulbapedia) Hitmonlee is a combination of hit, monster, and Lee (a reference to Bruce Lee). The name is also related to Hitmonchan and Hitmontop, both of which are parallel evolutions to it as of Generation II.