* Diversity: The animal kingdom is incredibly diverse. Many animals have four legs, but they belong to vastly different categories (mammals, reptiles, amphibians, etc.).
* Evolution: Some animals might have four legs as an adaptation to their environment, but they might have evolved from ancestors with a different number of legs.
* Scientific classification: Zoologists and biologists use specific terms to classify animals based on their evolutionary relationships, not just the number of legs they have.
Instead of a single name, here are some helpful terms:
* Quadrupedal: This is the scientific term for animals that walk on all fours.
* Tetrapod: This refers to all animals that have four limbs, including those with two legs (like birds) that evolved from four-legged ancestors.
* Mammals: Many mammals have four legs, but not all (like whales).
* Reptiles: Many reptiles have four legs, but some are legless (like snakes).
The best way to describe a 4-legged animal depends on the context and the specific animal you're talking about.