* Jellyfish: These are free-swimming, bell-shaped cnidarians with tentacles around the edge of their bell.
* Sea anemones: These are typically stationary cnidarians that resemble flowers with tentacles surrounding a central mouth.
* Corals: These are colonial cnidarians that form hard, calcium carbonate skeletons.
* Hydras: These are tiny, freshwater cnidarians that resemble miniature sea anemones.
The stinging cells are called nematocysts, which are specialized cells containing a coiled, barbed thread that can be rapidly discharged, injecting venom into the prey.
Note: Some other organisms, such as some types of worms, may also have tentacles, but they do not have stinging cells.
