A larva was a distinct form some animals took before transforming into their adult form.
In 2153, the ECS Horizon carried stromatopod larvae among its cargo, intended for the Demerians. (ENT: "Horizon")
The Pyrithian bat fed on moth larvae. (ENT: "Extinction")
The Norcadian Museum of Entomology had an exhibit of beetle larvae from the equatorial subcontinent of Norcadia Prime. (VOY: "Tsunkatse")
Photonic fleas were also known to produce larvae. (VOY: "The Voyager Conspiracy")
Larval forms notable by themselves included the tadpole, the Orillian lung maggot, the techno-larva, and the Lyssarian Desert Larvae. (TAS: "The Terratin Incident"; ENT: "The Shipment", "Similitude")