Does the fox hunt game exist professionally? I've just recently seen the new Tomb Raider movie and during the start of it, Lara is working as a cycle courier. Some members of it want to run a game called fox hunt, where you can win money if you manage to outrun the hounds.

The objective of the game, the fox is given a fake fox tail that is attached to their bike and a paint can which is punctured to leave a trail for the hounds to follow. The fox is given a head start and the hounds need to try and capture the fox by taking the tail off the fox's bike. If the fox manages to outrun the hounds and the paint can runs dry, the fox wins. They do this game in central London and isn't shown to be a fully legal game. The entire sport is done whilst riding their bikes.

Question is, has this game ever been done in a legal/professional context? If so, what examples of this competition are there? Are there also official rules for the game?
I've never heard of a fox hunt race in particular, but there is an extensive racing culture among bicycle couriers. These races are usually alleycat races, and generally involve riding to several checkpoints in sequence, sometimes performing tasks at those checkpoints.

Searching YouTube for bicycle messenger races, alleycat racing, and similar terms, will bring up many videos.

See also In Race of Bike Messengers, Potholes and Bad Manners Can Be Costly, a New York Times feature about the North American Cycle Courier Championship, a rare sanctioned race for which the city closed streets.