What is a caterpillar called before being a butterfly?

Quite interesting analysis. When the egg hatches out pops a caterpillar. It has six legs and may have a bunch of pseudo legs to help it keep attached to eats leaves etc. As it grows its outer skin doesn't stretch enough to contain the caterpillar so it splits and the caterpillar crawls out of it. This change from on skin size to the next is called an "Instar." When the butterfly completes its last instar, It attaches itself to a suitable foundation and hangs usually upside down and the skin splits for the last time are reveals a chrysalis with the morphing butterfly inside. In its time, the chrysalis splits open and the butterfly emerges. It takes several hours for the wings to expand and dry before the butterfly can fly.