Customer Tom Boddingham, 27, whose left foot is slightly longer than his right, placed a £15.50 order with Monster Slippers for a novelty pair of claws; instead of a size 14.5 left slipper, he received one that was 210cm (7ft) long - which sets the world record for the Largest slipper.
The Guinness world record for the largest shoe measures 5.50 m (18 ft 0.53 in) x 2.11 m (6 ft 11.07 in) and is 2.90 m (9 ft 6.17 in) high and was unveiled by the Nationaal Fonds Kinderhulp (Netherlands) in Amsterdam, the Netherlands.
Guinness World Records also recognized the world record for the Largest collection of shoe horns was set by Martien Tuithof (Netherlands), who has a collection of 1,594 shoe horns.
The World's Largest Slipper is almost as big as a Smart car and is more than large enough to act as a sleeping bag for two.
The British-based company blamed a translation error by its Hong Kong factory that led to a mix-up with a decimal point.
'We asked our factory to make one size 14.5 monster claw. His other foot fits our extra large,' a company spokesman said.
'They messed up and didn't notice the decimal point, so here we are with a blinking great slipper that's equivalent to a size 1,450,' or XXXXXXXXXXXXXXXXL.
Mr Boddingham said: 'It was sent directly from Hong Kong and measures the same length as a grizzly bear or a family car.
'I reckon I must be the owner of the biggest slipper in the world.'
Yes, you are, now!