[Snake]

If you gain the effects of Perfect Poise while Airborne, the visual effect will spawn around -15 Pixel_Y, downwards, from where it should (which is wherever Airborne tilts up your Pixel_Y).

Then if you land, it gets further displaced south.

You can easily replicate this by dodging an attack while airborne.

[Neus]

This should be corrected in 2.81 (v4), hopefully with no additional bugs for big mobs.