海百合 / Crinoid (sea lily / feather star)

I look like a sea flower, but I’m an animal—your wider animal family has excellent disguises!
我看起来像海里的花，却是动物——你广大的动物亲戚里，还有伪装高手！

Sources
Larval stages of a living sea lily (stalked crinoid echinoderm)
https://www.nature.com/articles/nature01236
Post-Paleozoic crinoid radiation in response to benthic predation preceded the Mesozoic marine revolution.
https://doi.org/10.1073/pnas.0914199107
Testing predator-driven evolution with Paleozoic crinoid arm regeneration.
https://doi.org/10.1126/science.1101009
Species reference
https://en.wikipedia.org/wiki/Crinoid

Research context
Crinoids are echinoderms, part of the broader deuterostome context shared with chordates. Their long fossil record documents marine ecosystems and a body plan very different from that of vertebrates.