Siege Monster. King Kong deals double damage to objects and structures.

Legendary Resistance (3/Day). If King Kong fails a saving throw, it can choose to succeed instead.

Multiattack. Kong uses frightful presence and makes four fist attacks

Fist. Melee Weapon Attack: +5 to hit, reach 15 ft., one target. Hit: 6 (10d6 +7) bludgeoning damage.

Frightful Presence. Each creature of King Kong’s choice that is within 120 feet of King Kong and aware of it must succeed on a DC 15 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 a success. If a creature’s saving throw is successful or the effect ends for it, the creature is immune to the Kong’s Frightful Presence for the next 24 hours. 

King Kong can take 3 legendary actions, choosing from the options below. Only one can be used at a time, and only at thee end of another creature’s turn. King Kong regains all spent legendary actions at the start of its turn. 

Ground Slam. Kong slams the ground. All creatures within 30 feet of the Kong must make a DC 18 Strength saving throw or fall prone and take 20 damage on a failed save, or half as much on a successful one. 

Attack. King Kong can make a fist attack. 

Throw. King Kong can throw a grappled creature or object. In an attempt to saved one self from said throw, one must make a DC 20 strength saving throw. On a failed saving throw or no resist, a target can be thrown 180 feet away. If they hit an object, they take 35 (10d6) bludgeoning damage. The throwing distance is halved for each size category above medium the target is.