Pets

Is possible get back normal pet appearance when is my pet to T4?

 

I am pretty sure, that you can just use a "token/coupon/pet", not quite sure which it is, but you Can change the appearance.
I don't know if this helps, but here is a list of the Pet appearances: https://bdo.mmo-fashion.com/pet-appearance-change-options/

This is the only thing I could find, on BDOcodex: https://bdocodex.com/gl/npc/7089/
That item is only 200 Pearls, BUT I have to admit, that I am not entirely sure, if it is possible to change the appearance, of a high Tier pet, into a low Tier pet