Animals that lay eggs are called-
Oviparous
Oviparous is correct.
Oviparous animals lay eggs, and the embryo develops inside the egg outside the mother's body until it hatches. Birds, most reptiles, amphibians, most fish and insects are oviparous.
Viviparous animals give birth to live young that develop inside the mother's body, as in most mammals, so the term mammals does not describe egg-laying as such.
Nulliparous is a term for a female that has never given birth; it is not a mode of reproduction.
In which type of reproduction does Hydra develop new individuals from a bud?