If you ever have an aquarium with them in you will find that they will just up and move some where else if they decide where tey are is not to their liking
Look at them like upside-down jelly fish that stick to rocks. People look at them more like underwater plants instead of the sedentary cousins of jellyfish.
Fungi are more related to animals than plants. Fungi produce "flesh."
Sea anemones are a group of predatory marine invertebrates constituting the order Actiniaria. Because of their colourful appearance, they are named after the Anemone, a terrestrial flowering plant. Sea anemones are classified in the phylum Cnidaria, class Anthozoa, subclass Hexacorallia. As cnidarians, sea anemones are related to corals, jellyfish, tube-dwelling anemones, and Hydra. Unlike jellyfish, sea anemones do not have a medusa stage in their life cycle.
They're a "plant" on the edge of creating a neural system while also producing "flesh."