The koteka, also referred to as a horim or penis gourd, is a penis sheath traditionally worn by native male inhabitants of some (mainly highland) ethnic groups in New Guinea to cover their penises. The koteka is normally made from a dried-out gourd, Lagenaria siceraria, although unrelated species such as pitcher-plant (Nepenthes mirabilis) are also used. The koteka is held in place by a small loop of fiber attached to the base of the koteka and placed around the scrotum. A secondary loop placed around the chest or abdomen is attached to the main body of the koteka.

Men choose kotekas similar to ones worn by other men in their respective cultural groups. For example, Yali men favour long, thin kotekas that help hold up the multiple rattan hoops worn around their waists, whereas men from Tiom wear double gourds held up with strips of cloth and use the space between the two gourds for carrying small items such as money and tobacco.