Massive lag spikes whenever you render animated skins

Whenever I render my friend who has this animated skin, it causes massive lag spikes to my game. I find this very annoying, and needs to be fixed soon. Also, it can be any animated skin. Look closely at the video for the lag spike.

Steps to Reproduce:

1. Join a multiplayer world with two accounts
2. On one account, equip an animated Character Creator item
3. Move away from the player with the animated item until the chunk they are in is unloaded
4. Move back to that player

Observed Results:
A lag spike occurs when the player is rendered.

Expected Results:
No lag spike should occur.