I'm just saying that they should try to make it look like what it would really be like if it was real.
But sometimes realism isn't the point of a particular art form, as with my Muppet and cartoon examples. Or as with traditional Japanese theater, which often uses puppets that are clearly puppets, operated by visible black-clad stagehands that the audience is trained by theatrical convention to ignore. I tend to see the creatures in tokusatsu
films as an extension of that theatrical tradition. They're meant to be stylized and symbolic rather than photorealistic. Some art forms require the audience to engage their own imaginations to enable them to accept what they see as real for the purposes of the narrative.