Large Dragon, lawful good
Armor Class 18 (natural armor)
Hit Points 178 (17d10+85)
Speed fly +80, swim +40, walk +40
Challenge 10
Saving Throws cha +9, con +9, dex +6, wis +5
Skills insight +5, stealth +6, perception +9, persuasion +9
Damage Immunities fire
Senses blindsight 30 ft., darkvision 120 ft., passive Perception 19
Languages Common, Draconic
Amphibious. The dragon can breathe air and water.
Multiattack. The dragon makes three attacks: one with its bite and two with its claws.
Bite. Melee Weapon Attack: +10 to hit, reach 10 ft., one target. Hit: 17 (2d10 + 6) piercing damage.
Claw. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 13 (2d6 + 6) slashing damage.
Breath Weapons (Recharge 5-6). The dragon uses one of the following breath weapons. **Fire Breath.** The dragon exhales fire in a 30-foot cone. Each creature in that area must make a DC 17 Dexterity saving throw, taking 55 (10d10) fire damage on a failed save, or half as much damage on a successful one. **Weakening Breath.** The dragon exhales gas in a 30-foot cone. Each creature in that area must succeed on a DC 17 Strength saving throw or have disadvantage on Strength-based attack rolls, Strength checks, and Strength saving throws for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.
Source: 5e Core Rules · OGL/Open