some guy running a business, who was selling a purple one with a green slit mouth and green skirt came up with the name "purple people eaters" to attract people to buying them a long time ago. they werent even considered anything special at the time.
its pretty common practice now for stores to give a coral a fancy name to encourage "rarity" and induce that it is special in some way, to encourage a sale. and, in some people's opinions naming things is just for fun, to describe the coral somehow and how it is different from others that may look like it.
in general, the people eater type polyps you refer to, the ones with the green slit mouths...are not zoanthids. they are a close relative called protopalythoas. people just give the protopalys with the green slit mouths the name "people eater" b/c its *cool* to do, and attracts more attention to selling etc.
you can name them whatever you want. no one has the last say to whether or not a certain zoa does or does not have a certain name.
i have yet to see a zoanthid god post in this forum, or a statement from a diver saying when they collect zoanthids, they come with tags that say something like "green smurfalator - made in taiwan" :lol:
