Like the minotaur beast of human legend, the Mythic Dragon can go from delighted to enraged in a moment's notice. Mythic Dragons aren't angry dragons in general, but they do get agitated by the color red.
If you're going to care for a Mythic Dragon, it's good to 'rage-proof' your habitat by keeping it away from anything red. Be sure to put your Fire Dragon habitats on the other side of the island, and make sure there are no open flames nearby.
It is possible to train a Mythic Dragon to get used to the color red. Start by regularly feeding Fireapples to your Mythic Dragon. After a while, the Mythic Dragon will associate the color red with happy emotions instead of angry ones.
Epic Mythic Dragons are in control of their emotions, and rarely have episodes, but this is a process that occurs naturally. It is best not to force this behavior on Epic Mythic Dragons, as they are still stubborn creatures. One Caretaker attempted to chain a Mythic Dragon and expose the dragon to various red objects. The Epic Mythic Dragon broke free from its iron chains and flew off, never seen by its Caretaker again.