This phylum is comprised of jellyfish, box jellies, anemone, corals, sea pens, hydrozoans. They used to be grouped together with comb jellies under the collective term coelenterates (Phylum Coelenterata). Jellyfish are well-known for their stinging tentacles, but there are some which do not sting. Box jellies look like the true jellyfish, but has a more box-liked look and are highly venomous. Anemones look like plants but are actually predatory animals. Their stings allow them to catch prey even though most of the time they are immobile. Corals are responsible for the huge coral reefs all over the world. Hard corals are actually colonies of individual polyps. Sea pens are named after the quill pens, which only some of the sea pens resemble. hydrozoans like as single individuals, like the Hydra, or in a colony, like the Portuguese Man o' War.