Ancient abyssal wurm

Pit of despair. Each creature that misses an attack roll against The wurm by 5 or more has disadvantage on all attack rolls and strength and charisma saves until the end of the wurms next turn.  

Multi color. Depending on the wurms color will show what damage it breath weapon does out of the following damage types acid, cold, fire, lightning, poison. 

Two Heads. The wurm has advantage on Wisdom (Perception) checks and on saving throws against being blinded, charmed, deafened, frightened, stunned, and knocked unconscious.

Multi attack. The wurm makes 2 double demonic bite attacks and its frightful presence. 

Demonic double bite. Melee Weapon Attack: +8 to hit, reach 10 ft., 1 target. Hit: 32 (6d8 + 8) [piercing] damage. 

Frightful Presence. Each creature of the wurm's choice that is within 120 ft. of the wurm and aware of it must succeed on a DC 18 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 itself on a success. If a creature’s saving throw is successful or the effect ends for it, the creature is immune to the wurm’s Frightful Presence for the next 24 hours.

2 way breath weapon (Recharge 5-6). The wurm exhales its breath in a 60-foot cone in 2 dirrections. Each creature in that area must make a DC 18 Dexterity saving throw, taking 63 (9d12) [check multi color] damage on a failed save, or half as much damage on a successful one.