It has three heads, and for every head you cut off, two more grow in its place.
the hydra
The Greek monster with nine heads is called the Hydra.
The Greek monster with nine heads is called the Hydra.
The Greek monster with nine heads is called the Hydra.
It was a hydra.
hydra
It is a hydra
The monster you are referring to is the Hydra. The Hydra is a child of Typhon and Echida.
Greek mythology has no chronology in our sense.
The Greek monster famously known for having 9 heads is the Hydra.
The Greek monster with 9 heads known for its ferocious nature is called the Hydra.
You may be referring to the Hydra, but the hydra was also said to have nine heads instead of six.