Legendary resistance 1/day. if the Yeaan fails a saving throw, it can choose to succeed instead.

Regeneration. Heal 26 at the start of every round.

Magical Resistance. This monster has advantage on saving throws against all spells made against him

Encase. The Yeaan can attempt to catch a creature in its body. The target the Yeaan is targeting must make a dex save of 21 or they are stuck inside the Yeaan. while inside you are restrained and take 5d6 acid damage at the end of every round. on a success, the target will still take 3d6 acid damage and not be restained.

Saber. Melee Weapon Attack: +15 to hit, reach 5 ft., 1 target. Hit: 25 (4d4 + 13) this weapon does not deal any type of damage, so it can not be resisted.

ray. RangedWeapon Attack: +16 to hit, range 60/120 ft., 1 target. Hit: 25 (3d4 + 14) can be any damage type the Yeaan desires.

swift. The Yeaan can attempt to dodge an attack, if it can pass a dex save of 21 than it succeeds and takes no damage.

The Yeaan can take 2 legendary actions a turn.

Ray. The Yeaan makes a ray attack.

Move. The Yeaan can move up to half it's speed.

Acid Splash (2 actions). The Yeaan spits up acid dealing 6d8 acid damage usless the target succeeds on a dex save of 21, in which case they only take half.