Have you guys noticed that the shadow of dragon may appear like a chopper in some situation?

Yesterday when we were preparing team fight for the dragon, i saw there was a shadow at the entrance of the dragon. It's like a chopper with four propellers. I remember when i saw it, the dragon hadn't respawned yet (but almost). I once thought it was caused by the project yasuo skin and i created a custom game to check but found nothing. Anyone met the same situation like me? BTW, the Phantom Pain is amazing :P