The animals that have no spine are invertebrates.
Insects - They have 6 paws.
Arachnids - They have 8 paws.
Crustaceans - They have several paws and often have claws.
Centipedes - They have many paws: they can reach a hundred!
Shellfish- They have a soft body, with or without shell.
Worms - They have a soft, cylindrical or flat body.