Metamorphosis is a biological process that involves a major change in an organism's form or structure. It can occur in many animals, including insects, amphibians, fish, and crustaceans. 

Instar formation is the developmental stage of an arthropod between molts. It occurs until the arthropod reaches sexual maturity. 

Ecdysis is the process of shedding an animal's outer layer or cuticle. It's also known as molting, sloughing, or shedding. 

Tagmosis is the evolutionary process by which segments of an arthropod's body are grouped together into larger, functional units called tagmata.