Mysterious street artist Banksy has put on an amazing exhibition in Bristol. People like his art, but nobody knows who he actually is and he likes to work in secret.
Most of the museum staff didn't know that Banksy was putting together an exhibition even though they worked in the building!
To make sure that the staff didn't go to work while things were being set up they were told that the museum was closed to film scenes from a Harry Potter film... but it wasn't!
Banksy managed to put up all his paintings and exhibits in just 36 hours. It's unusual for him to show his work in a museum - he got famous for his graffiti art on buildings.
Because Banksy used to paint in public some people don't like his work. They think it's graffiti and vandalism. Other people like it because they think it's funny.
This looks like a normal part of the museum in the natural history section, but what can you see if you look carefully?...
This is the rat from the previous picture. Up close you can see his little sunglasses, rucksack and spray paint can.
Banksy's art is famous for being slightly unexpected, like these fish fingers in a fish tank. You often have to look twice to see what's really there.
He uses his work to let people know his opinion about things, like these monkeys taking the place of politicians in the House of Commons.
Even though he keeps his identity a secret, it's known that Banksy used to live in Bristol. People think that this exhibition is his way of saying thank you to his home town.