Step 1: Understanding nitrogenous waste excretion.
Animals excrete nitrogenous wastes in different forms depending on their habitat and water availability. Step 2: Types of excretion.
Ammonotelic animals excrete ammonia and require more water.
Ureotelic animals excrete urea and require moderate water.
Uricotelic animals excrete uric acid and conserve maximum water. Step 3: Identifying the animal.
Lizard is a uricotelic animal and excretes uric acid as semi-solid paste. Step 4: Conclusion.
Therefore, lizard is a better conserver of water.