A squid is a type of fish that is often used to make calamari. It has eight tentacles, and a very elongated but distinct head on their bodies. Their tentacles are often separated into pairs of two. To be grammatically correct, they have four pairs of legs. The way they swim is really interesting. They are able to use their tentacles to propel themselves through the water. However, if they really get going, they can fly through the water.
Not literally, but there is quite a lot of energy created by the way they create the momentum. Calamari is served in high end sushi places. Lower end sushi places can serve it as well, but sometimes, the grade of the squid is linked to the price. A higher priced squid might make for better calamari.