I read the title of the video and realized that these critters are called Flying Rats/Flying Mice in japanese (tobinezumi). And I'll be damned if they don't look like some abomination spawned from a mouse/bird mating.
I want one, but I'm pretty sure that if I had one it would scare the hell out of me every time I saw it out of the corner of my eye.
It has weird little satyr legs! And in it's tiny T-Rex arms it could hold pan pipes. This is clearly Puck in his true form.