This galaxy cluster, which has been nicknamed «El Gordo» for the «big» or «fat» one in Spanish, is a remarkable object. Found in the distant Universe by Chandra and the Atacama Cosmology Telescope, El Gordo appears to be the most massive, the hottest, and gives off the most X-rays of any known cluster at its distance or beyond. In this composite image of El Gordo, X-rays are blue, optical data from the Very Large Telescope are red, green, and blue, and infrared emission from Spitzer is red. The comet-like shape of the X-rays, along with optical data, show that El Gordo is actually the site of a collision between two galaxy clusters, similar to the well-known Bullet Cluster.