While dragon skin can resist most spells, such as the Stunning Spell, some spells can affect dragons if aimed at the right spot, or if cast by several people at once.

• Conjunctivitis Curse: In the Triwizard Tournament of 1994, Durmstrang champion Viktor Krum used this curse on a dragon, with satisfying results.
• Draconifers: A transfiguration spell, it turns statues of dragons into real dragons, which can then be controlled by the caster.
• Stunnin Spell:
  The stunning spell has been known to affect dragons only when multiple
  wizards cast it simultaneously at the targeted dragon. In the Triwizard Tournament of 1994, Charlie Weasley and several other Dragonoligists used the Stunning Spell to successfully subdue several dragons.