Doppelganger Plant
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Doppelganger Plants are one of the many killer plants native to the Dungeons & Dragons setting of Ravenloft, although even in the Demiplane of Dread, they are believed to be of possibly alien origin. They're unabashed expies of the space-plants from the film Invasion of the Body-Snatchers!
They returned in Dungeons & Dragons 5th Edition under the new name of Bodytaker Plants.