This is a quick video I put together after doing an animation of a butterfly and a ladybug for the kid's educational application. The reference image of the flying insect had an odd way to animated the wings.
Rather than flap the wings they were just rotated. A way to animate wings that seems rather common. The deform instead of the rotation is not much hard but the results are a lot nicer in my opinion.
Here are the animations as gif images to get a better look at them:
I hope you enjoyed this quick video that is off topic but I will finish the complete game art series next and make the assets available