Great Wyrm Green Dragon (5e Creature)
From D&D Wiki
Great Wyrm Green Dragon
Gargantuan dragon, lawful evil
Saving Throws Dex +11, Con +19, Wis +16, Cha +17
Poison Absorption. Whenever the dragon is subjected to poison damage, it takes no damage and instead regains a number of hit points equal to the poison damage dealt.
Magic Resistance. The dragon has advantage on saving throws against spells and other magical effects.
Legendary Resistance (5/Day). If the dragon fails a saving throw, it can choose to succeed instead.
Siege Monster. The dragon deals double damage to objects and structures.
Multiattack. The dragon can use its Frightful Presence. It then makes five attacks: one with its bite and four with its claws.
Bite. Melee Weapon Attack: +20 to hit, reach 15 ft., one target. Hit: 21 (2d10 + 10) piercing damage plus 17 (5d6) poison damage.
Claw. Melee Weapon Attack: +20 to hit, reach 10 ft., one target. Hit: 17 (2d6 + 10) slashing damage.
Tail. Melee Weapon Attack: +20 to hit, reach 20 ft., one target. Hit: 19 (2d8 + 10) bludgeoning damage.
Frightful Presence. Each creature of the dragon's choice that is within 240 feet of the dragon and aware of it must succeed on a DC 25 Wisdom saving throw or become frightened for 1 minute. A creature that is frightened is also paralyzed. 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's saving throw is successful or the effect ends for it, the creature is immune to the dragon's Frightful Presence for the next 24 hours.
The dragon can take 5 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's turn. The dragon regains spent legendary actions at the start of its turn.
Detect. The dragon makes a Wisdom (Perception) check.
See 5e SRD:Dragons.