Thunder

Thunder was an Arabian horse that formerly belonged to Prince Adam as a child.

Biography
Thunder was originally Prince Adam's pet horse as a child. However, though he frequently rode it, he never gave it any love and compassion. Frequently just riding it then just resting near a tree. One day, Adam was about to ride the horse as usual, but Thunder, evidentially having had enough of his loveless existence under Adam, took the opportunity to escape into the forest. Even though Adam ordered for his soldiers to retrieve the horse, they never found it. Adam deep down proceeded to miss the horse, and presumably regretted his treatment of it. It was rumored to have been found by an enchantress and ridden as her horse, and proceeded to be supplied with love and affection. Mrs. Potts and the other servants relayed this story when expressing doubts about Adam, by that point turned into the Beast, being capable of redemption.

Trivia

 * Thunder was a character introduced in the thirteenth and final issue in a flashback to the Beast's childhood prior to the curse, as a glimpse as to what Adam was formerly like. It is not clear whether the enchantress that found Thunder is the same enchantress that cursed him into his Beast form or not.