Mammillaria prolifera, commonly known as the Texas nipple-cactus, West Indian nipple-cactus, grape cactus, or hair-covered cactus, is a species of cactus native to North America. Three subspecies are currently recognized: M. prolifera subsp. prolifera (Cuba, Dominican Republic, and Haiti), M. prolifera subsp. arachnoidea (Mexico), and M. prolifera subsp. texana (Mexico and the United States). The subspecies differ in overall size, the number and color of the spines, and the shape and color of the flowers. The plant's round or slightly elongated stems usually form small, dense clusters, and flowers are commonly born alongside fruit. It is one of the most popular and widely grown Mammillaria species.

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