Squid are cephalopods, which are the largest and most active invertebrates. The most common type of squid is the Humboldt or jumbo squid, which can grow up to 6 feet in length. The body parts of a squid include the tentacles, the digestive system, the head, the mantle and the beak.
Squid tentacles are lined with sharp, barbed suckers that are used to catch prey. Squid usually have 10 tentacles, making them decapods.
The squid digestive system is composed of a digestive gland, a stomach and what is called the funnel, which is where the squid excretes used food material.
The head consists of the brain and sensory organs. The head is actually connected to the foot, which holds the tentacles, hence the name cephalopod, which means "foot to head."
The mantle is the largest part of the squid. It is the large shell-like structure on a squid that holds and protects its major organs.
The squid beak is composed of hard tissue that allows the squid to tear up bits of food. Squid are partially carnivorous, so the beak may sometimes help to actually tear up another squid.