Tlaloque.

In iehoantin, y, moteneoa tlaloque: intech tlamiloia in mistli, in quiauitl, in teciuitl, in cêpaiauitl, in aiauitl, in tlapetlaniliztli, in tlatlatziniliztli, in teuitequiliztli. = These [gods] were called Tlalocs. To them were attributed clouds, rain, hail, snow, mist, sheet lightning, thunder, and lighting bolts which struck men. (central Mexico, sixteenth century)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 7 -- The Sun, Moon, and Stars, and the Binding of the Venus, No. 14, Part VIII, eds. and transl. Arthur J. O. Anderson and Charles E. Dibble (Santa Fe and Salt Lake City: School of American Research and the University of Utah, 1961), 18.

The Atlcahualo (ceasing of water, rain), was the name of the first festival of the year. The ceremonies practiced at this time were meant to ensure the rains would come again. They included the sacrifice of small children, preferably children with two cowlicks in their hair, considered like whirlpools, and sometimes called "banderas humanas." The children would be sacrificed atop hills or mountains associated with the tlaloque (Tláloc deities). Other tlaloque are Nappatecuhtli, Opochtli, Tomiyauhtecuhtli (one of the four hundred rabbits that were deities of pulque), and the tepictoton, small legless figures.
Bernardo Ortiz de Montellano, "Las hierbas de Tláloc," Estudios de cultura náhuatl 14 (1980), 287–314, see p. 290.