What is an animal which doesnt have a skeleton for example worm called this?

Animals without a skeleton are called invertebrates.

Worms are a good example of invertebrates. Other examples include:

* Arthropods: insects, spiders, crabs, lobsters

* Mollusks: snails, clams, squid, octopuses

* Echinoderms: starfish, sea urchins, sand dollars

* Cnidarians: jellyfish, corals, anemones

* Sponges

There are many different types of invertebrates, and they come in all shapes and sizes. They play important roles in ecosystems around the world!