When using Pixelmon Reforged (https://reforged.gg) the pixelmon mod, if you have their cosmetics enabled they follow a weird hitbox that flies all over the place, as shown in the video.

To reproduce you'd need a cosmetic from pixelmon, the easiest one to get would be signing up to the pixelmon forums, then linking your account through their program & you get a free robe & hat similar to the one shown in the video.

https://imgur.com/a/SSx7Uxk

Context (please complete the following information):

• MoBends 1.12.2 1.0.0 beta 20.0.6.20
• Pixelmon 1.12.2 8.1.2