What Oxford vs Cambridge race occurs at Spitalfields City Farm every year?

Not the more famous "Boat Race," but rather a "Goat Race."

It seems that at the farm in question, two goats imaginatively named Oxford and Cambridge go "horn to horn." The winner gets the "King Billy" title and an edible reward.

This "event" which has all the hallmarks of a student prank, began in 2009 and has become an all-day festival, replete with atrocious caprine puns.

https://www.timeout.com/london/things-to-do/everything-you-need-to-know-about-the-oxford-v-cambridge-goat-race