It is Britain's version of The X-Files. Tucked away in the Natural History Museum in London are the laboratories of the Identification and Advisory Service.
It is here that experts scrutinise the array of strange objects discovered by the public - from apparent dragon skulls to objects that appear to come from outer space.
The most recent case is particularly baffling - a mass of slime found on a nature reserve after reports of a meteor streaking through the skies.
"The slime is still a genuine mystery," said Chesca Rogers, who is leading the effort to identify the gelatinous material.
"There are stories in folklore that link it with meteor sightings. Some people think it might be unfertilised frog spawn, others think it is a fungus, or a slime mould or that it is plant-related."
References to "star jelly" date back to the 16th century.
The discovery this week of more slime, at a time when frogs are not spawning, has deepened the mystery further.
Generally, most oddities are quickly uncovered as something altogether ordinary.
John Tweddle, manager of the centre, said: "Sea bird pelvises can look like the right shape for a dragon's skull, so we get people saying they think they have found a dragon."
Just R20 for the first month. Support independent journalism by subscribing to our digital news package. 
