Echinocactus, also known as the barrel cactus, is a type of cactus that belongs to the Echinocactaceae family. The name "echinocactus" derives from the Greek word "echinos" which means "hedgehog," referring to the spines on the cactus. There are several synonyms for the word echinocactus. One of the most common is "golden barrel cactus," which refers to the yellowish-green color of the cactus. Another synonym is "horse crippler," which is a term used by some Native American tribes who believed that the cactus could cause lameness in horses if they stepped on it. Other synonyms include "compass cactus," "fishhook cactus," and "barrel prickly pear".