Now that we have a good idea of what distinguishes animals from other living things, we’re ready to look at them in a little more detail. In the next chapter, we’ll discuss some of the relevant terminology. We’ll also take a look at the history of animal life.
Most people use the term "nymph" when referring to juvenile insects (those that have direct development), crustaceans or the like. I've never seen it used for a vertebrate.
Their relative inefficiency may be one reason why almost all prokaryotes are single-celled (unicellular) organisms.
Interesting, I did not know there were multicellular prokaryotes. Though 'multicellular' seems a bit of a stretch when all they do is clump together in a ball while they wait for less dry times.