Linked from
The 8 pages that link to Polyp (zoology), each with the reason it gives.
CnidariaRelated: Corals, anemones, and hydras exemplify this common cnidarian form.
HydrozoaRelated: Many hydrozoans live as polyps, sometimes forming colonies.
Sea anemoneRelated: The sea anemone is a large, solitary polyp rather than a jellyfish-like medusa.
Chrysaora fuscescensRelated: Its life cycle includes a small attached polyp stage.