The Solar Pyrehawk and Felstorm Dragon (and perhaps other mounts using the same models, I can’t confirm) both flicker and glitch while dragonriding, especially while banking/turning. The model flickers rapidly into a non-tilted stance, making it quite hard to look at them because they flicker so much!
Update- it’s all mounts on both sketelons! So the bird skeleton (parrots, rogue class hall ravens, etc) and storm dragon skeleton (which does not seem to be shared with regular drakes, as I don’t see them clipping/glitching as much)