In Galician, Portuguese and Brazilian folklore, it is the seventh of the sons (but sometimes the seventh child, a boy, after a line of six daughters) who becomes a werewolf.

This belief was so extended in Northern Argentina (where it is called the "lobizon"), that seventh sons were abandoned, ceded in adoption or killed.

A law from 1920 decreed that the President of Argentina is the godfather of every seventh son. Thus, the State gives him a gold medal in his baptism and a scholarship until his 21st year. This ended the abandonments, but it is still traditional that the President godfathers seventh sons.