A Sydney Aquarium diver uses a vacuum to clean the gravel in the Great Barrier Reef tank as a Ray Shark swims by September 26, 2006 in Sydney, Australia. The Aquarium is undergoing its annual spring clean to prepare for the school holidays using vacuums, along with sea creatures like Sea Cucumbers, Sea Urchins, Cleaner Wrasse Fish and Sea Stars to help complete the job. (Photo by Ian Waldie/Getty Images)

A sign marks a railway crossing next to the troubled Kruemmel nuclear power plant on June 2, 2011 in Geesthacht, Germany. The German government recently announced it will phase out the country's 17 remaining nuclear reactors by 2022 in a policy initiative that represents a radical reversal from its previous policy and was sparked by the disaster at Fukushima. Kruemmel went into operation in 1983 but was taken offline following a fire in 2007. (Photo by Sean Gallup/Getty Images)

Demonstrators march on a Slutwalk on June 4, 2011 in Glasgow, Scotland. Glasgow's first ever sl*t walk made its way through the town center streets in a bid to raise awareness about commonly-held attitudes towards rape and sexual assault. (Photo by Jeff J Mitchell/Getty Images)

KALTENBERG, GERMANY - JULY 08: Actors dressed as knights perform during the traditional Kaltenberg knight tournament on July 8, 2007 in Kaltenberg, Germany. With around 120,000 visitors each year, the festival including knight tournaments, medieval styled markets and a variety of music performances, the event is one of the biggest of its kind. (Photo by Johannes Simon/Getty Images)

Pionneers from Aubagne's 1st Foreign Regiment (Legion etrangere) march the Champs-Elysees during the annual Bastille day parade on July 14, 2011 in Paris, France. The French National Day celebrates its revolution in the storming of the Bastille in 1789 through various parades and official ceremonies throughout France. (Photo by Franck Prevel/Getty Images)

Bulls fight during the annual Bullfighting Festival on March 17, 2010 in Cheongdo, South Korea. More than 130 bulls from South Korea and abroad charge and lock horns in the annual festival which was run March 21, 2010. The bulls are grouped into three weight categories and fight head on until one of the bulls turns its head and runs away. (Photo by Chung Sung-Jun/Getty Images)

The name Danbo is a pun on the Japanese word for corrugated cardboard “danboru” (ダンボー). There’s also a company in Japan which makes cardboard boxes which has Danbooru in its name.