It's rare for a dragon to elect another creature to inherit its power, but when it does occur, chaos reigns for a time when the creature will go on a rampage of gluttony, rapidly gaining in mass, muscle and monstrosity. Eventually, after they become as bloated as a blimp, they will settle back down into their old masters lair and slumber. Slumbering until their body and mind properly reorganize their new found knowledge, magic and weight.