Rhaegal, the Emerald Dragon

Flying, haste
Fire (At the beginning of combat on your turn, if this
creature isn't enchanted with an Aura with Blood,
it attacks an opponent at random if able. Only one
Aura with Blood can be attached to this creature.)
Jon Snow: "I don't know how to ride a dragon!
What if he doesn't want me to?"
Daenerys: "Then I've enjoyed your company,
Jon Snow."