Step 1: Regeneration in animals.
Regeneration is the ability of an organism to regrow lost body parts or regenerate from a part of the body.
Step 2: Organisms capable of regeneration.
In this case, Hydra is known for its remarkable ability to regenerate any part of its body, making it one of the most common examples.
Step 3: Conclusion.
Thus, the correct answer is ((C) Hydra.
Final Answer:
\[
\boxed{\text{Hydra}}
\]