There are three types of animals classified on the basis of excretory waste:
A. Ammonotelic animals (major excretory waste is ammonia) - Many bony fishes, aquatic amphibians, aquatic insects.
B. Ureotelic animals (major excretory waste is urea) - Marine fishes, many terrestrial amphibians (like a frog), and mammals.
C. Uricotelic animals (major excretory waste is uric acid) – Insects, land snails, reptiles, and birds.
Uric acid is water-insoluble and is excreted in the form of a white paste or powder. The production of uric acid is energetically costlier, but it includes much-reduced water loss.
Among the given examples, Pavo is the genus of birds and peacock belongs to the same genus. So, it will be releasing the nitrogenous waste in the form of pellets or paste.