Euphorbia obesa resembles a ball, thornless and decorative. It is commonly known as 'baseball plant' due to its shape. Its diameter is between 6 cm and 15 cm depending on its age. Young plants are spherical, but become cylindrical with age. They contain water reservoirs for periods of drought. It almost always shows 8 ridges adorned with small deep gibbosity regularly planted on the edges. It is green with horizontal lighter or darker stripes. In the wild, and with exposure to direct sunlight, it shows red and purple areas. The plant is dioecious, which means that a subject has only male or female flowers. The small flowers are insignificant in apex. In fact, like all Euphorbia, flowers are called cyathia. As in all Euphorbia species, the latex is toxic. Living in similar conditions on two different continents, Euphorbia obesa presents a form of convergence with Astrophytum asterias which is a cactus from Mexico.