Here's a little showcase of a small build that's been loitering in the sky above my base that I think some people could get a kick out of.

They aren't perfect representations of the flaptors seen in the movie but I feel they're as close as reasonably possible with a tweaks made so they work better in minecraft. Those changes being the front wings are a bit longer than the back set, I prefer them this way but it's easy to change if not. However there is a major height difference between the wings, which was done so they are more visually distinguished from a distance.

The builds are really small and not very resource/labour intensive, biggest problem being the fact you need some crimson planks. I won't provide instructions, the build's are small enough and should be doable with the picture provided :)

A single flaptor consists of the following:

1x Crimson plank slab
1x Crimson trapdoor
1x Jack 'o Lantern
1x Acacia fence gate
2x Acacia trapdoors
4x String
4x White carpet
6x Iron trapdoors (4 if you'd rather have shorter front wings)
?x Temporary blocks for string placement and building these in the sky.

Enjoy :)