The term hatchling referred to the newborn offspring of species who hatched. Hatchlings might be accommodated using a hatchery.
Gorn hatchlings were sometimes hatched on breeding planets. After the SS Puget Sound was captured by the Gorn in the 2230s or 2240s, the crew and passengers were deposited on one such planet to be eaten alive by hatchlings. La'an Noonien-Singh was the only survivor. (SNW: "Strange New Worlds", "Memento Mori")
Other species producing hatchlings included Xindi-Insectoids, Reptohumanoids, and Vilix'pran's species. (ENT: "Hatchery"; VOY: "Parturition"; DS9: "Heart of Stone")