Ancient Land Drake

Innate Spellcasting.  The land drake's spellcasting ability is Wisdom (spell save DC 18).  The land drake can innately cast the following spells, requiring no material components:

At will:  create or destroy water, detect magic, detect poison and disease, speak with animals, speak with plants

3/day each:  dispel magic, hallucinatory terrain, lesser restoration, pass without trace

1/day each:  awaken, commune with nature, wrath of nature

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

Magic Resistance.  The drake has advantage on saving throws against spells and other magical effects.

Traceless Presence.  If surrounded by enough loose soil and vegetation to do so, the drake can take 10 minutes to bury itself in the ground, becoming a part of the landscape, indistinguishable from its surroundings.

Multiattack.  The drake makes three attacks:  one with its bite, one with its claws, and one with its tail.

Bite. Melee Weapon Attack:  +14 to hit, reach 15 ft., one target.  Hit:  19 (2d10 + 8) piercing damage.

Claws. Melee Weapon Attack:  +14 to hit, reach 10 ft., one target.  Hit:  15 (2d6 + 8) slashing damage.

Tail. Melee Weapon Attack:  +14 to hit, reach 20 ft., one target.  Hit:  17 (2d8 + 8) bludgeoning damage.

The drake can take 3 legendary actions, choosing from the options below.  Only one legendary action option 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.

Cast Spell.  The drake casts one of the spells from its 'at will' list.

Tail Attack.  The drake makes a tail attack.

Shaking Footfall (Costs 2 Actions).  The drake stomps hard upon the ground.  Each creature within 15 feet of the drake must succeed on a DC 22 Dexterity saving throw or take 15 (2d6 + 8) bludgeoning damage and be knocked prone.