Killing a full-grown lion with only a spear would be an incredibly dangerous and highly unlikely scenario. Lions are powerful predators with sharp claws, strong jaws, and great speed and agility. They are apex predators and are well-equipped to take down large prey.
While it is true that ancient humans used spears and other primitive tools to hunt large animals, it's important to recognize that hunting a lion with a spear is an extremely risky and difficult task. Lions are formidable opponents, and attempting to confront one with only a spear would put the human at a severe disadvantage.
In modern times, hunting large predators like lions is heavily regulated and often illegal due to conservation efforts and the protection of endangered species. Killing a lion or any other endangered animal without proper authorization is not only unethical but also illegal and punishable by law in many countries.
Overall, hunting and harming wild animals, especially endangered species, should be strongly discouraged. Instead, efforts should focus on wildlife conservation, habitat protection, and coexistence with these magnificent creatures to ensure their survival for future generations.