Michael Phelps' race with a virtual shark, was widely deemed as a massive disappointment, but it is not the first time an athlete has competed against an a beast.
As part of the Discovery Channel's 'Shark Week'. Phelps raced a virtual shark in an open-water race that left viewers disappointed.
Here are some of the most memorable occasions where an athlete faced off against an animal, with mixed results for both sides.
Nicholas Roche vs. Moonbi Creek
Weeks after the 2014 Tour de France, Roche turned up to Leopardstown to race the Dermot Weld-trained Moonbi Creek in a two-furlong race.
Despite Roche's rolling start, Moonbi Creek was the comfortable winner with Pat Smullen on board. Titled as 'Beast vs. Bike', the race raised much-needed funds for Our Lady’s Hospital in Crumlin.
Bryan Habana vs. Cheetah
Having just won the 2007 Rugby World Cup with South Africa, Habana was handed a different challenge. Widely regarded at the time as the fastest man in rugby, Habana was challenged to race a cheetah for charity.
'A Race Against Time' was created in a bid to create awareness for the plight of cheetahs. Despite a 50-metre headstart, Habana and the animal finished together in a virtual dead-heat.
Kobayashi vs. Giant Bear
In 2003, Japanese competitive eater Takeru Kobayashi took part in a hot-dog eating contest against a bear that weighed more than 1,000 lbs.
The made-for-TV event was broadcast by Fox and saw legendary boxing MC Michael Buffer introduce the duo. Unsurprisingly, the giant bear was victorious in what can only be described as a dark day for competitive eating.
Jesse Owens vs. Horse
After turning professional, Jesse Owens decided to run against a horse in a bid to earn much-needed funds, after his Olympic exploits.
Taking place in December 1936 in Cuba, the star of the previous summer's Olympics was the half-time entertainment in a football match taking place in Havana. The 100-yard race saw Owens have a headstart, and despite the horse cutting across the track, he still won comfortably.
Dennis Northcutt vs. Thelma
A former wide-receiver with the Cleveland Browns and Jacksonville Jaguars, Northcutt raced an ostrich in the ESPN show Sport Science.
In a bid to find what was the fastest mammal on two feet, Northcutt easily won the 40-yard dash. Despite the win, he was also able to catch the ostrich when chasing him.