What is the name of the king of the Carnival in many traditions?

The name of the king of Carnival in many traditions is King Momo.

King Momo is a ceremonial figure who presides over Carnival celebrations in countries including Brazil and Colombia. His appearance traditionally marks the opening of the festivities, and he may receive a symbolic key to the city. In Portuguese he is called Rei Momo; Spanish-speaking celebrations commonly use Rey Momo.

The character derives from Momus, a figure in Greek mythology associated with satire, mockery, and criticism. Carnival’s playful reversal of social order makes this humorous, larger-than-life character a fitting ruler. In some countries, Momo is represented by a costumed person; in parts of Argentina and Uruguay, a large papier-mâché figure may lead the celebrations.

King Momo is not the same as a historical monarch or a universal Carnival official. Each festival may choose its own representative, and the role’s customs vary by city.