Adult Blue Dragon
Huge Dragon (chromatic), Lawful EvilAC 19
HP 212 (17d12 + 102)
Speed 40 ft., burrow 30 ft., fly 80 ft.
STR
25 (+7)
Save +7
DEX
10 (+0)
Save +5
CON
23 (+6)
Save +6
INT
16 (+3)
Save +3
WIS
15 (+2)
Save +7
CHA
20 (+5)
Save +5
Saving Throws DEX +5, WIS +7
Skills Perception +12, Stealth +5
Immunities Lightning
Senses Blindsight 60 ft., Darkvision 120 ft., Passive Perception 22
Languages Common, Draconic
CR 16
Traits
Legendary Resistance (3/Day, or 4/Day in Lair). If the dragon fails a saving throw, it can choose to succeed instead.
Actions
Multiattack. The dragon makes three Rend attacks. It can replace one attack with a use of Spellcasting to cast Shatter.
Rend. Melee Attack Roll: +12, reach 10 ft. Hit: 16 (2d8 + 7) Slashing damage plus 5 (1d10) Lightning damage.
Lightning Breath (Recharge 5+). dex 19, each creature in a 90-foot-long, 5-foot-wide Line. Failure: 60 (11d10) Lightning damage. Success: Half damage.
Legendary Actions
Cloaked Flight. The dragon uses Spellcasting to cast Invisibility on itself, and it can fly up to half its Fly Speed. The dragon can't take this action again until the start of its next turn.
Sonic Boom. The dragon uses Spellcasting to cast Shatter. The dragon can't take this action again until the start of its next turn.
Tail Swipe. The dragon makes one Rend attack.