Venom Grub

Venom Grubs were a species used by the Slitheen family to dispose of unwanted members. Blon claimed that if she didn't follow the criminal activities of the rest of the family, she would have been fed to the Venom Grubs by her father. (TV: Boom Town)

Behind the scenes
"Venom grub" was also the name given to the larvae guns in Bill Strutton's novelisation of The Web Planet.