Nearly 1500 people tackled the "beast"— a 7km track over hilly farmland at Haruru Falls that included rolling in swamps and mud pits before being hosed down by firefighters.
The popular Fullers GreatSights Bay of Islands Beast on Friday and Saturday was the Bay's muddiest and toughest race where participants could challenge themselves as individuals of were invited to team up and wear fancy dress.
It was the fourth year the event, organised by Sport Northland, has been held with 450 school students racing on Friday and then about 1000 competing on Saturday. It is the biggest field to date.
Entries sold out a week before the event.
Sport Northland's chief operating officer Brent Marwick said it was the driest year but rain at the start of winter provided the ideal platform for participants to have fun, especially in the swamps and mud pits.
"The event is all about getting out there and having fun and the feedback we got was everyone had a great time. It's a tough event to compete in but people enter it primarily for fun," he said.
Bagpiper Bruce Finlayson provided entertainment at different stages of the event while firefighters from Paihia were ready to hose down competitors at the finish line.
After coming second in 2016 and third last year, Ritchie Crawshaw from Dargaville took out the men's division in 40.10s, Whangarei's Darren Spratt came second in 41.56s and Levi Cohen finished third place in 42.24s.
Chubby Upton from Whangarei won the women's division in 42.45s, second was Kaitaia's Emily McDowell and Whangarei's Sarah Morris finished third.
The secondary schools event on Friday attracted 450 participants which was 200 more than last year.
Mason Younger of Kerikeri High School finished top in the boy's division, Broadwood Area School's Wiremu Emery came second and William Tattersfield of Huanui College third.
The girl's division was won by Bree Monaghan of Whangarei Girls High School.
Taipa Area School's Sharee Lange came second and Trista Comer of Otamatea High School third.
The winners had an added bonus of not only winning a Fullers GreatSights cruise but also receiving meat packs from AFFCO.