Can't Be Done On Peaceful Difficulty.
I Built Walls Around My Town And Then Filled Them With Archers. If The Dragon Sticks Around To Firebreath More Than Once, It Should Die.
- Ballista Towers Do A Lot Of Damage To It. Build Them On Towers To Increase Their Range.
- Around Year 100, The Red Dragons Turn Into Black Dragons. Which Have Way More Health.
(Normal Difficulty)
Achievement Pops As Soon As It Dies.
Good Luck!