AAA

 Outburst of anger. When AAA takes the first hit, he gets angry. He deals double damage and doubles his speed.

Fear. When his Hit-Points fall under the half of the maximum, he rolls in a ball and is invincible. This takes two rounds. After that he activates his Outburst of anger 2.

Outburst of anger 2. Now AAA is really angry. He doubles the damage again, his speed increases by 10 ft. and he can use his multi-attack twice in one round.

Stone. AAA only takes half damage.

Life of anger. When AAAs Hit-Points fall to 0, he stand up again with full life. But now he disappears and appears in a random point in the world. When the players find him again, he attacks immediately. Every time he dies he deals 1d4 more damage and every second time he dies he gets one more AC.

Multi-attack. AAA makes six attacks: four with his fist, one with his foot and one with any attack he wants.

Fist. Melee weapon attack: +14 to hit, reach 7 ft., one target. Hit: 10 (2d8+ 5) bludgeoning damage. 

Foot. Melee weapon attack: +14 to hit, reach 5 ft., one target. Hit: 15 (3d10 + 10) bludgeoning damage.

 Scream. Ranged weapon Attack: +16 to hit, range 30 ft., 10 targets. Hit: 10 (3d8 + 8)  physical damage.

Claw. Melee weapon attack: +12 to hit, range 5 ft., one target. Hit: 15 (4d10 + 10) slashing damage.

Bite. Melee weapon attack: + 12 to hit, range 3 ft., one target. Hit: 15 (4d8 + 8) pricing damage.

Extra attack. AAA can use every attack he wants as a bonus action.

Revenge. When AAA takes damage, he uses his Multi-attack.