Passage Dragons

Travelers in the Passage of Caverns know there are many dangers within the tunnels but none evoke as much fear as the roar of a Passage Dragon. These powerful lords of the underground are known to have molten lava breathe that can reduce enemies to bubbling piles of bone in short order and are able to teleport through the rock of their earthen domains. Often merchant caravans keep a rare piece of treasure on hand to placate any that they may come across; even if it rarely happens.

Passage Dragon CR: 14

Huge dragon, neutral evil

Armor Class: 19 (natural armor)

Hit Points: 160 (16d12 + 56)

Speed: 40 ft , fly: 80 ft , burrow: 30 ft

STR

20 +5

DEX

10 +0

CON

18 +4

INT

20 +5

WIS

16 +3

CHA

18 +4

Saving Throws: CON +9, WIS +8, CHA +9

Skills: Perception +7, Persuasion +12

Damage Resistances: Fire, Poison, Psychic; Bludgeoning, Piercing, and Slashing from Nonmagical Attacks

Condition Immunities: Charmed, Frightened, Poisoned

Senses: Blindsight 60 ft., Darkvision 150 ft., Passive Perception 17

Languages: Common, Draconic, Undercommon

Challenge Rating: 14

The dragon’s innate spellcasting ability is Charisma (spell save DC 17, +9 to hit with spell attacks). The dragon can innately cast the following spells, requiring no material components:

At will: catapult (as a 2nd-level spell), earth tremor

1/day: conjure elemental

3/day: thunderwave (as a 5th-level spell), heat metal, meld into stone (Can perceive area around it), shatter

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

Actions

Multiattack. The dragon makes one Bite attack and two Claw attacks.
Bite. Melee Weapon Attack: +10 to hit, reach 10 ft., one target. Hit: 16 (2d10 + 5) piercing damage plus 5 (1d10) fire damage.

Claw. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 8 (1d6 + 5) slashing damage.

Tail. Melee Weapon Attack: +10 to hit, reach 10 ft., one target. Hit: 9 (1d8 + 5) bludgeoning damage. If the target is a creature, it must succeed on a DC 17 Strength saving throw or be knocked prone.
Change Shape. The dragon magically transforms into any creature that is Medium or Small, while retaining its game statistics (other than its size). This transformation ends if the dragon is reduced to 0 hit points or uses its action to end it.
Molten Lava Breath(Recharge 5–6). The dragon exhales a cloud of lava in a 40-foot cone. Each creature in that area must make a DC 17 Dexterity saving throw. On a failed save, the creature takes 44 (8d10) fire damage, and the lava burns the creature for 1d4 rounds. On a successful save, the creature takes half as much damage with no additional effects. A burned creature takes 3d6 fire damage at the start of its turn and can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

Legendary Actions

The dragon can take 3 legendary actions, choosing from the options below. Only one legendary action can be used at a time and only at the end of another creature’s turn. The dragon regains spent legendary actions at the start of its turn.
Rock Sweep. The dragon sweeps its tail against the rocks of its lair. Rocks shoot out in a 15-foot cone. Any creature within that cone must make a Dexterity saving throw. On a failure, they take 3d6 bludgeoning damage and their speed is reduced by 10 for 1d4 rounds.
Tail. The dragon makes one Tail attack. Earthen Transposition (Costs 2 Actions). Using its meld into stone ability, the dragon can disappear into the stone of its lair and teleport to a point within its lair. It then can attack once using a claw attack.

Lair Actions

On initiative count 20 (losing initiative ties), the dragon can take one of the following lair actions; the dragon can’t take the same lair action two rounds in a row:
Deep Torpor. The dragon casts the slow spell, requiring no spell components and using Charisma as the spellcasting ability (spell save DC 17). The spell ends early if the dragon uses this lair action again or if the dragon dies.
Volcanic Activity. Noxious gasses fill the lair and any creature that needs to breathe must make a Constitution saving throw DC 17. On a failure, they are sickened and can only use an action or movement on their turn.

Unsure Footing. The dragon causes the earth in its lair to be uneven and constantly shifting. All creatures in the lair must make a Dexterity saving throw DC 17 or be knocked prone and must use its next turn to stand up and can not take any other actions.
Regional Effects The region surrounding a legendary deep dragon’s lair is altered by the dragon’s magic, creating one or more of the following effects:

Unbearable Heat. The temperature around the lair is stifling hot, all creatures in the area must drink double their normal amounts of water in order to survive or become dehydrated.
Restless Sleep. When a creature finishes a long rest within 6 miles of the lair, the creature must first succeed on a DC 10 Constitution saving throw or be unable to reduce its level of exhaustion. Creatures immune to the poisoned condition are immune to this effect.
Rejuvenating Waters. The hot springs near the lair are beneficial for health. Any creature that spends at least 1 hour inside it during short rest regains double the amount of health from their hit die.
If the dragon dies, these effects fade over the course of 1d10 days.

Passage Dragons live in expansive caverns that are often only accessible through one passageway. They have ways out of their own lairs that other creatures would not access.
The challenge rating of a legendary deep dragon increases by 1 when it’s encountered in its lair.

They appear to be dragons whose scales are like the walls of the caverns in which they reside. Lava-like veins run throughout the cracks in their scales. Their tails are slightly shorter than most dragons.