Calisto

Also Galician: https://gl.wikipedia.org/wiki/Lista_de_nomes_masculinos_en_galego#N
http://www.ige.eu/igebdt/esq.jsp?idioma=gl&ruta=onomast/nomes.jsp

It is also a feminine name. Calisto was a nymph from Greek mythology, one of Zeus' lovers. Hera, the wife of Zeus, turned her into a bear, and Zeus, merciful, put her in the sky, as the Ursa Major.

This is also a female name in Spanish. It's the Spanish form of Callisto/Kallisto, the name of the Greek nymph. It's not really used outside of mythology, though.