Examining a giant fatberg isn't a job we'd like to do, but scientists in Devon have been doing just that.
It was discovered just before last Christmas when it was a whopping 64 metres long and blocking sewers under the town of Sidmouth.
At the time, the company responsible for the area's water, South West Water (SWW), said it was the biggest it had ever found and that it would take eight weeks to remove!
A team of scientists from the University of Exeter have been trying to work out how it was created and whether it could have caused any environmental risks.
From looking at small samples, the team found that cooking fats and hygiene products, such as wet wipes, played a big part in making the mass.
They even found some false teeth in there. Yuck!
While it might sound pretty grim, scientists have also said that they found "no evidence of harmful viruses or bacteria" which means although it might have been causing a blockage, it wasn't harmful to people or the environment.
Andrew Roantree, from South West Water, said: "Although we deal with around 8,500 blocked sewers every year, the Sidmouth fatberg was by far the largest discovered in our service history. We wanted to learn as much as we could about it, how it was created and what it was made of to help us avoid further fatbergs in future."
It's now hoped that what the scientists have discovered, can be used to encourage people not to put things down their sinks or loos which should go in the bin instead.