What is the strongest Hydra in mythology?

Could you please elaborate on the question of what is considered the strongest Hydra in mythology? Is it referring to the mythical creature with multiple heads that grows back when one is cut off, and if so, are we talking about the one from Greek mythology or perhaps another culture's interpretation? Additionally, are we assessing strength based on its regenerative abilities, its physical prowess, or its symbolic meaning? Clarifying these points would greatly assist in providing an accurate and informative response.