The ouroboros
A snake that eats its tail
Ouroboros is Greek for devouring its tail. One of the earliest known appears in Egypt, on a gilded shrine from the tomb of Tutankhamun, in the 14th century BCE. By the 3rd century CE an alchemical text from Alexandria, the Chrysopoeia of Cleopatra, drew it as a sign of eternity.
Here it stands for something narrower: growth that feeds on what it stands on, until there is nothing left to eat.