Londoners who did a double-take while bustling about the city yesterday had good reason. There was a fish, or rather a duck, out of water.

Spotted floating down the city's River Thames was a giant yellow rubber duck, a 50-foot-tall publicity stunt intended to give residents a good laugh.

The duck was reportedly sent down the Thames on a barge by Jackpotjoy.com, a top gambling website in the U.K., to promote its newly-launched FUNdation that, "grants FUNds for daft ideas!," according to its website.

The Jackpotjoy FUNdation was launched after a poll commissioned by the site found that Victoria Beckham, Jeremy Clarkson, Tom Cruise and Madonna topped the list of the least-fun celebrities. In response, the site decided to launch a competition to offer rewards for Britons who submitted the most fun and wacky ideas to help people, "take life a little bit less seriously."

The first step was floating the duck, with bright red lips, down the Thames, and even having the Tower Bridge's drawbridge raised so it could pass through.

"2012 really has been the year of the River Thames with the Jubilee Pageant, the floating Olympic rings and David Beckham jetting into the ceremony via speedboat," British actress Barbara Windsor, a FUNdation spokesperson, said, according to the UPI. "We decided to round off the year with the giant duck and it certainly cheered everyone up … no-one could suppress a smile as they saw it sailing past."

Interested, and humorous, Britons can submit their fun ideas on the FUNdation's Facebook page, and then hope that they will win either "FUNding" to follow through with their idea or a cash reward for performing it.