Euphorbia horrida major Nova - African Milk Barrel Cactus. Native to South Africa and mimics a barrel cactus. This is a milk cactus. Likes a lot of sun and kept dry. This one will stretch if not given at least 6 hours of light. It will loose its compact form. Keep from long periods of cold.
 
** Plants and pot size may vary from photos.  These plants are available at the greenhouse if you visit.