Bound Until Death. When the dramalgamation reaches 0 HP, its form is released from its curse, freeing the dragons within it. For every head that has not been cut off from its form, the dramalgamation melts into one ancient dragon (red, blue, green, black, white and shadow respectively). The dragons are stunned for 2d4 rounds. The DM chooses whether the dragons are friendly, neutral or hostile.

Draconic Gibbering. The dramalgamation babbles incoherently while it can see any creature and isn’t incapacitated. Each creature that starts its turn within 60 feet of the dramalgamation and can hear the gibbering must succeed on a DC 17 Wisdom saving throw. On a failure, the creature can’t take reactions until the start of its next turn and rolls a d8 to determine what it does during its turn. On a 1 to 4, the creature does nothing. On a 5 or 6, the creature takes no action or bonus action and uses all its movement to move in a randomly determined direction. On a 7 or 8, the creature makes a melee attack against a randomly determined creature within its reach or does nothing if it can’t make such an attack.

Actions

Multiattack. The dramalgamation can use its Frightful Presence. It then makes two crush attacks and one tail attack.

Crush. Melee Weapon Attack: +19 to hit, reach 10 ft., one target. Hit: 19 (2d8 + 10) bludgeoning damage.

Whip. Melee Weapon Attack: +19 to hit, reach 20 ft., one target. Hit: 17 (2d6 + 10) bludgeoning damage.

Frightful Presence. Each creature of the amalgamation’s choice within 120 feet of it and aware of it must succeed on a DC 17 Wisdom saving throw or become frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, with disadvantage if the amalgamation is within line of sight, 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 amalgamation’s Frightful Presence for the next 24 hours.

Dragon Breath (Recharge 4-6). The dramalgamation extends a dragon head from its mass and uses one of the below breath weapons at random. The dramalgamation has six heads in total, which can be attacked (AC 22; 100 hit points; only immune to the element of its breath weapon). Once a dragon head has been cut off, the dramalgamation can no longer use its breath weapon and loses immunity to its element. The head only has immunity to the element listed beside the breath weapon. At the start of the dramalgamation’s turn, all heads retract back into its mass.

1: Red Dragon Head. Exhales fire in a 90-foot cone. Each creature in that area must make a DC 21 Dexterity saving throw, taking 91 (26d6) fire damage on a failed save, or half as much damage on a successful one. This head has immunity to fire damage.

2: Blue Dragon Head. Exhales lightning in a 120-foot line that is 10 feet wide. Each creature in that line must make a DC 23 Dexterity saving throw, taking 88 (16d10) lightning damage on a failed save, or half as much damage on a successful one. This head has immunity to lightning damage.

3: Green Dragon Head. Exhales poisonous gas in a 90-foot cone. Each creature in that area must make a DC 22 Constitution saving throw, taking 77 (22d6) poison damage on a failed save, or half as much damage on a successful one. This head has immunity to poison damage.

4: Black Dragon Head. Exhales acid in a 90-foot line that is 10 feet wide. Each creature in that line must make a DC 22 Dexterity saving throw, taking 67 (15d8) acid damage on a failed save, or half as much damage on a successful one. This head has immunity to acid damage.

5: White Dragon Head. Exhales an icy blast in a 90-foot cone. Each creature in that area must make a DC 22 Constitution saving throw, taking 72 (16d8) cold damage on a failed save, or half as much damage on a successful one. This head has immunity to cold damage.

6: Shadow Dragon Head. Exhales shadowy fire in a 90 foot cone. Each creature in that area must make a DC 21 Dexterity saving throw, taking 84 (24d6) necrotic damage on a failed save, or half as much damage on a successful one. A humanoid reduced to 0 hit points by this damage dies, and an undead shadow rises from its corpse and acts immediately after the dramalgamation in the initiative count. The shadow is under the dramalgamation’s control. This head has immunity to necrotic damage.