monoped
/ˈmɒnə(ʊ)pɛd/(also monopede)
adjective
1Having only one foot or one leg; relating to the possession of one foot or one leg.
2Performed on only one foot; one-legged. rare.
noun
A person, animal, or thing having only one foot or one leg.
Origin
Early 19th century. From mono- + -ped. Compare post-classical Latin monopes, adjective and noun, French monopède monster with only one foot.