Red Dragons and Black Dragons are level 7 creatures of Dungeon, and are recruited from the Dragon Cave.
Red and black dragons with their great mobility, flying ability, and powerful breath attack are among the most effective units in the game. Red dragons are immune to spells below level four. Black dragons are twice as durable, do 150% damage to giants and titans, and are immune to all spells. This spell immunity is a double-edged sword, though, as it makes both Red and Black dragons immune to most beneficial spells, including Resurrection. Placing Hydras or any living Dragons in the Skeleton Transformer will give you Bone Dragons instead of regular Skeletons.
See also