Banksy, a grafitti artist from Bristol, UK, smuggled this dead rat in a glass box into the Natural History of Museum in April 2004, where it was "exhibited" for several hours as staff didn't notice that anything amiss.
The piece called "Banksus Militus Ratus" was displayed with a text that said the common sewer rat had some remarkable new characteristics.
"Attributed to an increase in junk food waste, ambient radiation and hardcore urban rap music these creatures have evolved at an unprecedented rate."
It quotes a bogus university professor as saying: "You can laugh now ... but one day they may be in charge."
Banksy's manager, Steve Lazarides, said museum visitors liked the rat exhibit and claimed one staff member had thought it was genuine: "I saw a member of staff walk up to it, check it was attached properly, read the text and walk away.