The immature forms of animals which they are before metamorphosis are the larva.
Step-by-step explanation:
The larva in plural form is known as the larvae. The eggs are hatch into the form of larva. These larvae grow in different stages which are marked according to the stages as I or II and so on.
After the larval development, when they are ready to be converted into adults, metamorphosis occurs. This process changes the larva into adults. Here the immature form gets converted into mature adult form.