There can be a very thin line between cute and creepy. Just look at Chucky, M3GAN, or the Cabbage Patch Kids. Not all of these are killer toys, but all of them could be believably beloved by children while giving grown-ups the heebie-jeebies. Coming to join their perturbing plaything ranks is Chauncey Bear in Imaginary. Plus, like Blumhouse’s other recent killer toy offerings, M3GAN and Five…