Kingdom Animalia

To solve the problem, we need to identify which of the given organisms can exhibit regeneration — the biological process by which organisms replace or restore lost or amputated body parts.

1. Understanding Regeneration:
Regeneration is the ability of an organism to regrow certain parts of its body that are lost due to injury. Some organisms have exceptional regenerative capabilities.

2. Evaluating the Options:
- Planaria: ✅ Known for extraordinary regeneration; can regrow entire body from a small fragment.
- Homo sapiens: Humans have very limited regenerative capacity (e.g., skin, liver).
- Pavo cristatus (peacock): No significant regenerative abilities.
- Naja naja (cobra): No regenerative capability.

Final Answer:
The organism that exhibits regeneration is Planaria.