I had never heard of a fatberg before reading this Yahoo article. But now that I know fatbergs exist, I want to see one, if only for scatological reasons.
Fatbergs are composed largely of cooking oil that has been poured down drains while hot and runny. Once in the cold water of the sewer system, however, the fat congeals. The solid mess then combines with “wet wipes.” The wipes are frequently labeled as “disposable” but are turning out not to be.
Cooking oil + wet wipes = fatberg, it turns out.