From BR Bullpen
The golden sombrero comes from hockey's hat trick, three goals in a game. Thus a batter who strikes out three times in a game is said to wear the "sombrero". The word in Spanish refers to any type of hat, but in popular culture it is associated with the unwieldy huge hats worn by stereotypical cartoon Mexicans. More grand than a hat would be a sombrero that is gold. It is awarded to any player who strikes out four times in a game. A platinum sombrero for five strikeouts or a titanium sombrero for six strikeouts may be awarded but they are much rarer than a golden sombrero.
A player may also take the collar when he has a golden sombrero.
The king of the Golden Sombrero is Ryan Howard, who at the end of 2015 had 27 games with 4 or more strikeouts in his career.