Birds, reptiles, and land snails excrete nitrogenous waste mainly as uric acid in the form of a semi-solid pellet or paste, which conserves body water.

Among the listed options, Pavo (peacock) is a bird and exhibits this uricotelic excretion. The others are a monotreme mammal (Ornithorhynchus), an amphibian (Salamandra), and a fish (Hippocampus), none of which excrete uric acid as the principal nitrogenous waste in pellet form.