Any of various invertebrate animals that resemble plants in morphology (form) or mode of life more than that of an animal: The sea anemones, corals, and sponges are considered to be zoophytes.

Sponges, for example, are just barely animals. In fact, they are such a borderline case that until the nineteenth century they were called zoophytes, the animal-plants. Sponges are among the most primitive forms of multicellular animal life.