Make your own sprites of the characters in a relaxed pose and when the relaxation is initiated, change sprites and when the relaxation is over, change sprites back.

That simple.

"why I've gotta be one of the cool kids just to walk by/
- without being tripped, thrown down on the ground and kicked/
Insulting me for no reason, I was treated like shit/
The teachers let it happen/
I've even seen some of them teachers laughing/
That's why I had a smile on my face when I started blastin/" - Ill Bill - The Anatomy of a School Shooting