Ancient Earth Dragon

Earth Glide. The dragon can burrow through nonmagical, unworked earth and stone without disturbing it.

False Appearance. While the dragon remains motionless within its linked area, it is indistinguishable from a natural rocky outcropping.

Legendary Resistance (3/Day). When the dragon fails a saving throw, it can choose to succeed instead. When it does, it becomes more like rock. Its Speed, burrow speed, and flying speed are halved until the end of its next turn.

Essence Link. The essence dragon is spiritually linked to a specific area or landmark. The dragon gains no benefit from a long rest when more than 1 mile away from its linked area. If the dragon dies, the area it is linked to loses its vital essence until it forms a new essence dragon, which can take centuries. When a creature first enters an area that has lost its vital essence in this way, they gain a level of fatigue and a level of strife. This fatigue and strife can be removed only by completing a long rest outside the area.

Innate Spellcasting. The dragons spellcasting ability is Charisma (save DC 17). It can innately cast the following spells, requiring no material components. 3/day each:locate animals or plants, spike growth, stone shape, wall of stone, 1/day:earthquake, move earth

Multiattack. The dragon attacks once with its bite and twice with its slam. In place of its bite attack it can use Rock Spire.

Bite. Melee Weapon Attack: +15 to hit, reach 15 ft., one target. Hit: 35 (5d10 + 8) piercing damage. Instead of dealing piercing damage the dragon can grapple the target (escape DC 23) and a Huge or smaller creature grappled in this way is restrained. While grappling a creature the dragon can't bite another target.

Slam. Melee Weapon Attack: +15 to hit, reach 10 ft., one target. Hit: 21 (3d8 + 8) bludgeoning damage and the target is pushed up to 10 feet away falling prone if it impacts a wall or other solid object. This attack deals an extra 9 (2d8) bludgeoning damage if the target was already prone.

Scouring Breath (Recharge 5-6). The dragon exhales scouring sand and stones in a 90-foot cone. Each creature in that area makes a DC 23 Dexterity saving throw taking 70 (20d6) slashing damage on a failed save or half damage on a success. A creature that fails the save is also blinded until the end of its next turn.

Rock Spire. A permanent 25-foot-tall 5-foot-radius spire of rock magically rises from a point on the ground within 60 feet. A creature in the spires area when it appears makes a DC 21 Dexterity saving throw taking 18 (4d8) piercing damage on a failure or half damage on a success. A creature that fails this saving throw by 10 or more is impaled and restrained at the top of the spire. A creature can use an action to make a DC 13 Strength check freeing the impaled creature on a success. The impaled creature is also freed if the spire is destroyed. The spire is an object with AC 16 30 hit points and immunity to poison and psychic damage.

The dragon can take 3 legendary actions. Only one legendary action can be used at a time and only at the end of another creatures turn. It regains spent legendary actions at the start of its turn.

Shake the Foundation. The dragon causes the ground to roil, creating a permanent, 40-foot-radius area of difficult terrain centered on a point the dragon can see. If the dragon is bloodied, creatures in the area make a DC 23 Dexterity saving throw. On a failure, the creature takes 21 (6d6) slashing damage and falls prone. On a success, the creature takes half damage.

Slam Attack (Costs 2 Actions). The dragon makes a slam attack.

Entomb (While Bloodied. The dragon targets a creature on the ground within 60 feet, forcing it to make a DC 17 Dexterity saving throw. On a failure, the creature is magically entombed 5 feet under the earth. While entombed, the target is blinded, restrained, and can't breathe. A creature can use an action to make a DC 17 Strength check, freeing an entombed creature on a success.