Cnidaria

I've always found this phylum super interesting. Cnidaria is a divese phylum of animals. Some members of this group are not thought of animals by some members of the general public such as corals, or Anthazoans. This phylum also includes the jellyfish, or scyphozoans. I find this amazing that corals are relatively closely related to Jellyfish.
The word Cnidaria is a derivative of the Greek word 'cnidos' meaning stinging needle. Most of members of this phylum have some sort of defense mechanism that is centred around having these stinging needles. As a phylum they are really interesting and beautiful.