Frostheart is a made up character created by Shinecloud.
Frostheart is a bright white tom with no other speck of any color on him and blue eyes. When he was born his mother thought he was blind, but it turned out he was just arrogant. He has a constant attitude of anger, and thinks ThunderClan is to 'soft' for him. He is later thougth to acutally not be as tough as he seems, for in Frostheart's Pet, he saves a mouse's life and makes friends with it.
He features on the ThunderClan roleplay page and in the fanfic Frostheart's Pet.