b'Thunderbird \n'b'  Gargantuan   monstrosity ,  unaligned  \n'b'  Armor Class  16 (natural armor)  Hit Points  248 (16d20 + 80)  Speed  20 ft., fly 120 ft.\n'b' STATS STR: 28 (+9) DEX:  10 (+0)  CON:  20 (+5)  INT:  10 (+0)  WIS:  16 (+3)  CHA:  9 (-1)  \n'b'\n'b'\n'b'\n'b'\n'b'\n'b'\n'b'  Saving Throws   Dex  +5,  Con  +10,  Wis  +8,  Cha  +4  Skills   Perception  +8  Damage Immunities  lightning, thunder  Senses  passive  Perception  18  Languages  \xe2\x80\x93  Challenge  13 (10,000 XP) \n'b' SPECIAL TRAITS \n'b'\n'b'  Innate Spellcasting . The thunderbird\xe2\x80\x99s innate spellcasting ability is  Wisdom  (spell save DC 16). The ancient one can innately cast the following spells, requiring no components:\n'b'\n'b'\n'b'  At will :  call lightning  (cast as a 6th-level spell),  commune with nature ,  gust of wind ,  wind wall  \n'b'\n'b'  Keen Sight and Hearing . The thunderbird has advantage on  Wisdom  ( Perception ) checks that rely on sight. \n'b'  Storm Healer . Whenever the thunderbird is subjected to lightning or thunder damage, it takes no damage and instead regains a number of  hit points  equal to the lightning or thunder damage dealt. \n'b'  Storm Rider . The thunderbird is continuously surrounded by stormy weather, as if it had cast  control weather , making all weather conditions within 5 miles one step more severe and all conditions within 500 feet two steps more severe. Its movement and senses are never impeded by wind, fog, rain, snow, or other weather effects. If the thunderbird is killed, these stormy weather conditions persist for 1d6 days centered on the site of its death. \n'b'  Thunderflash . When the thunderbird is struck in melee with a metal weapon, the attacker takes 7 (2d6) lightning and 7 (2d6) thunder damage and must make two saving throws as the thunderbird\xe2\x80\x99s thunderstrike ability, as if struck by three attacks in the same round. \n'b'  Thunderstrike . If the thunderbird hits a creature two or more times in one round, that target must make a DC 19  Constitution  saving throw, being  stunned  for 1 round on a failed save, or  deafened  for 1 round on a success. If the thunderbird hits with all three attacks in one round, the target must make a DC 18  Dexterity  saving throw or be  blinded  for 1 round. \n'b'\n'b' ACTIONS \n'b'\n'b'  Multiattack . The thunderbird makes three attacks: one with its beak and two with its talons. \n'b'  Beak .  Melee Weapon Attack : +14 to hit, reach 15 ft., one target.  Hit : 27 (4d8 + 9) piercing damage plus 7 (2d6) lightning and 7 (2d6) thunder damage. \n'b'  Talons .  Melee Weapon Attack : +14 to hit, reach 10 ft., one target.  Hit : 23 (4d6 + 9) slashing damage plus 7 (2d6) lightning and 7 (2d6) thunder damage and the target is  grappled  (escape DC 19). Until this grapple ends, the target is  restrained  and takes an additional 7 (2d6) lightning and 7 (2d6) thunder damage each round at the start of its turn. The thunderbird can grapple one Large or smaller creature with each of its talons, and until a grapple ends it can\xe2\x80\x99t use that talon on another target. \n'b'\n'b' LEGENDARY ACTIONS \n'b' The thunderbird 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 thunderbird regains spent legendary actions at the start of its turn. \n'b'\n'b'  Search . The thunderbird makes a  Wisdom  ( Perception ) check. \n'b'  Swoop . The thunderbird flies up to its speed and makes one talons  attack . \n'b'  Thunderbolt (2 Actions) . If the thunderbird has already cast  call lightning , it calls down a  lightning bolt  with its action. One-half of the damage from this bolt is lightning damage and one-half is thunder damage. \n'b'\n'b' ABOUT \n'b' Thunderbirds bring the storm on their wings. In times of drought, they are welcomed with joy and celebration. In other times, they are placated with gifts in hopes that they might leave quickly before flooding begins. When angered, thunderbirds can call down hurricanes and lay waste to entire villages, so in regions where these birds dwell, many villages maintain extensive rituals designed to appease and honor the local thunderbirds. Thunderbirds nest near the base of waterfalls, where the constant thrum of crashing water prepares the hatchlings for a life at the heart of a storm. Once the chicks have hatched, their parents carry the offspring to nests at the top of mountains, where the young are struck by their first bolts of lightning and learn the mysteries of the storm.'