It is a kind of "echinoderm." An echinoderm is a kind of sea animal with spiny skin. The spines on the skin of the starfish look like little bumps.
Starfish cannot swim. They crawl and climb. Most starfish are less than eight inches across, but a few kinds can be as big as a small car!
Starfish have "arms." Most have five, but some have as many as twelve! Each arm has a "foot" on the end. Each foot has a "sucker" that helps the starfish stick to rocks and catch his food. The suckers are like suction cups.
Their spiny skin is not very tasty to other sea creatures. Sometimes a fish will bite off a starfish's arm, but the starfish can grow a new one! If a starfish has its center part and one arm, it can live. The new arms grow back in a few months.
Starfish breathe through their feet. They also have little breathing tubes all over their bodies.
Starfish don't have eyes, but on the tip of each of each arm they have an "eyespot."
The mouth of the starfish is on their underside, in the middle. They eat shellfish. Using the suckers on their feet, they pull open the shell of the shellfish. Then, they push their stomach inside the shell and slowly digest the fish.