Where is the sleeping mystic Pokemon in fire red?

There is no "sleeping mystic Pokémon" in Pokémon FireRed. This phrase doesn't refer to any specific Pokémon in the game.

Could you please clarify:

* What Pokémon are you thinking of? Can you provide its name or a description?

* What makes it "mystic"? Is it a Psychic type?

* Where have you heard about this Pokémon? This might give us more context.

Once you provide more information, I can help you find it!