>>55016763>Scarlet: Sightings of this Pokémon have occurred in recent years. The name Great Tusk was taken from a creature listed in a certain book. >Violet: This creature resembles a mysterious Pokémon that, according to a paranormal magazine, has lived since ancient times.The wording in all languages is pretty explicit in drawing out differences to how similar they appear to be. There are even differences between the ones we know and the ones described in Occulture in some cases, which gives further credence to the point that these were specifically a product of our professor.
You don't really need to get this deep into the rabbit hole if you just look at how they are in the books compared to in-game, though. They're just markedly different and we don't really know how they got to that point other than there being some connection between the imaginary sketch and Iron Leaves / Walking Wake.