If you're using a texture pack and the Piglin/Zombified Piglin texture has a higher resolution than the default Minecraft Piglin/Zombified Piglin texture, their textures will appear glitched.
It does not seem to happen with the Piglin Brute though.
(The texture pack used in the screenshot is the Greek Mythology texture pack, but it can also happen with any other texture pack with high resolution entities)
Edit: Apparently, this issue can happen with any texture pack that's not the default one, regardless of its resolution.