b'Dragon, Aionian \n'b'\n'b'  Huge   dragon ,  chaotic evil  \n'b'  Armor Class  19 (natural armor)  Hit Points  230 (20d12 + 100)  Speed  40 ft.\n'b' STATS STR: 22 (+6) DEX:  10 (+0)  CON:  21 (+5)  INT:  16 (+3)  WIS:  17 (+3)  CHA:  16 (+3)  \n'b'\n'b'\n'b'\n'b'\n'b'\n'b'     Saving Throws   Dexterity +6,  Constitution +11,  Wisdom +9,  Charisma +9  Damage Immunities  acid, poison  Damage Resistances  bludgeoning, piercing, and slashing from nonmagical attacks  Condition Immunities   poisoned ,  prone   Skills   Perception  +9,  Stealth  +6  Senses   darkvision  120 ft., passive  Perception  19  Languages  Draconic  Challenge  17 (18,000 XP) \n'b' Special Traits \n'b'   Legendary Resistance (3/Day) . If the dragon fails a saving throw, it can choose to succeed instead. \n'b'  Acid Blood . A creature within 5 feet of the aionian dragon takes 5 (1d10) acid damage whenever it hits the dragon with a  melee attack  that deals piercing or slashing damage. \n'b'  Wakeful . The aionian dragon never sleeps. \n'b'  Actions \n'b'   Multiattack . The dragon can use its Frightful Presence. It then makes two attacks: one with its bite and one to constrict. \n'b'  Bite .  Melee Weapon Attack : +12 to hit, reach 10 ft., one target.  Hit : 17 (2d10 + 6) piercing damage plus 7 (2d6) acid damage. \n'b'  Constrict .  Melee Weapon Attack : +12 to hit, reach 15 ft., one Large or smaller creature.  Hit : 17 (2d10 + 6) bludgeoning damage. The target is  grappled  (escape DC 20) if the aionian dragon isn\xe2\x80\x99t already constricting a creature, and the target is  restrained  until this grapple ends. \n'b'  Acid Breath (Recharge 5-6) . The dragon exhales acid in a 60-foot cone. Each creature in that cone must make a DC 14  Dexterity  saving throw, taking 54 (12d8) acid damage on a failed save, or half as much damage on a successful one. \n'b'  Frightful Presence . Each creature of the dragon\xe2\x80\x99s choice that is within 120 feet of the dragon and aware of it must succeed on a DC 17  Wisdom  saving throw or become  frightened  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. If a creature\xe2\x80\x99s saving throw is successful or the effect ends for it, the creature is immune to the dragon\xe2\x80\x99s Frightful Presence for the next 24 hours. \n'b'  Swallow . The aionian dragon makes one bite  attack  against a Medium or smaller target it is grappling. If the attack hits, the target is also swallowed, and the grapple ends. While swallowed, the target is  blinded  and  restrained , it has total  cover  against attacks and other effects outside the aionian dragon, and it takes 21 (6d6) acid damage at the start of each of the aionian dragon\xe2\x80\x99s turns. An aionian dragon can have only one creature swallowed at a time. If the aionian dragon takes 30 damage or more on a single turn from the swallowed creature, the aionian dragon must succeed on a DC 19  Constitution  saving throw at the end of that turn or regurgitate the creature, which falls  prone  in a space within 10 feet of the aionian dragon. If the aionian dragon dies, a swallowed creature is no longer  restrained  by it and can escape from the corpse by using 15 feet of movement, exiting prone. \n'b'  Tail .  Melee Weapon Attack : +12 to hit, reach 15 ft., one target.  Hit : 15 (2d8 + 6) bludgeoning damage. \n'b'  Legendary Actions \n'b' The aionian dragon can take 3 legendary  actions , choosing from the options below. Only one legendary action option can be used at a time, and only at the end of another creature\xe2\x80\x99s turn. The aionian dragon regains spent legendary  actions  at the start of its turn. \n'b'   Detect . The dragon makes a  Wisdom  ( Perception ) check. \n'b'  Tail Attack . The dragon makes a tail  attack . \n'b'  Chomp (Costs 2 Actions) . The aionian dragon makes one bite  attack  or uses its Swallow. \n'b'  About \n'b' This serpent\xe2\x80\x99s crest shines with a golden gleam. Its eyes flash like fire and its whole body is suffused with venom. \n'b' Between its triple rows of teeth, its three-forked tongue flickers. \n'b'  Nature\xe2\x80\x99s Guardian . Aionian dragons are guardians by nature and when not hunting, spend most of their time resting in riverside caves. They are extremely territorial and will attack any perceived intruders.'