Cockfighting

Cockfighting was a sporting event outlawed on Federation planets.

In cockfighting, two aggressive birds were forced to fight in an arena, sometimes to the death, while a bookmaker managed a betting pool for people to gamble on the outcome. The sport had been outlawed on Earth for hundreds of years by 2267. 

The term was also used to describe unarmed combat that was particularly violent, masculine, or deadly.

History
In 2249, George Samuel Kirk brought 16-year-old James T. Kirk to first visit the newly constructed USS Enterprise (NCC-1701), then brought him along on a trip with Robert April and others on a route that let them study the Rosette trinary in the Rosette Nebula. But the Enterprise was ambushed by , an opportunistic pirate spacecraft piloted by Angus Burgoyne and Roy John Moss. After hiding in the nebula for repairs, Enterprise emerged to attack the Shark, and George Kirk called the upcoming battle a cockfight. 

In 2267, James Kirk, Spock, and Montgomery Scott went undercover to track missing male Gharian wedding birds stolen from the Federation wildlife preserve planet Salvum. In the absence of females during their mating season, the males grew to four times their normal size and became hyper-aggressive. Scott believed that the birds were taken to the non-aligned asteroid Grotus, because animal fights were the preferred type of gambling on Grotus. However, once there, the Starfleet officers stood out, and Scott was quickly captured by hoodlums led by Zarcun-5 and placed into a large arena to face one of the birds. As the spectators watched, bookmakers gave 40:1 odds that Scott would be killed in less than ten minutes. 

Also in 2267, the Enterprise recovered lifepods during a battle as the massive, armored Fury ship Rath wrecked ten Klingon battle cruisers. When General Kellen’s disabled cruiser helplessly tumbled toward Fury, Kirk ordered the Enterprise to move in close with tractor beams to prevent a collision. Kirk thought that he as well as the Enterprise as herself were eager to join what he considered a cockfight.