Sint Holo is a mystical, invisible, horned serpent which appeared to males who were extremely wise in the mythologies of many Native Americans. Sequoya, the inventor of the Cherokee alphabet, was said to have seen Sint Holo. He brought rain and make a noise similar to (but not the same as) thunder.

He may have origins in Maya mythology or Aztec mythology. Sint Holo was venerated, in various forms, by the Cherokee, Chippewa, Choctaw, Chickasaw, Creek and Catawba.