In this visual ethnography I show several features of the Feast of Corpus Christi celebrated in San Mateo del Mar (Tehuantepec, Oaxaca, México), with a special focus on Snake Dance. In order to give an appropiate context to the photographies, taken June, 7h 2012, I will try first to locate Corpus day into San Mateo’s ceremonial cycle, remarking its role as a rainmaking ritual. Later, I will introduce the two main characters of the dance (Neajeng, the lightning bolt or Archer, and Omalndiük, the Snakehead), and the other dancers (the das), as well as their clothing and the highlights of the dance´s dynamic development.