Q: hydra を使った例文を教えて下さい。
A: The Greek Hydra from myth is a terrifying, many headed beast. The Hydra had a special ability, where if one of its nine heads was cut off, two more would grow back in its place.

Like the Hydra of myth, multifaceted problems like unemployment are hard to tackle. These hydras reveal new problems underneath the obvious ones, and need good strategies to be handled properly. If left with only a few fixes, hydra-like problems can get even worse than they were when you started. (It's a real hydra of a problem - everytime we fix a problem, two more spring up to take its place!)

Hydras are also a genus of small, predatory, freshwater cnidarians. They are closely related to jellyfish, and similarly sting their prey. These hydras have thin, tubular bodies, with a cluster of tentacles at one end. They are named after the Greek monster.