Mutated insect larvae created by the green chemical waste pumped into a disused coal mine in Llanfairfach, Wales. The maggots were an off-shoot from the green slime, that killed on contact, known as The Green Death. It was created by Global Chemicals, a result of the callousness of BOSS, the firm's mainframe computer's artificial intelligence.

The maggots bred and at least one hatched into a giant flying insect. They were destroyed by a fungus grown by Professor Jones, a scientist dedicated to alternative options other than waste-producing technology..