Young Blue Dragon

Desert Farer. The dragon ignores difficult terrain or obscurement caused by sand or gravel, even while flying. Additionally, it ignores the effects of extreme heat.

Dune Splitter. The dragon can remain submerged in sand and gravel for up to 4 hours. It has advantage on Stealth checks to hide in this way.

Innate Spellcasting. The dragons spellcasting ability is Charisma (save DC 15). It can innately cast the following spells, requiring no material components. 3/day each:blur, silent image

Multiattack. The dragon attacks once with its bite and twice with its claws.

Bite. Melee Weapon Attack: +9 to hit, reach 10 ft., one target. Hit: 21 (3d10 + 5) piercing damage plus 4 (1d8) lightning damage.

Claw. Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit: 14 (2d8 + 5) slashing damage.

Lightning Breath (Recharge 5-6). The dragon exhales a 60-foot-long 5-foot-wide line of lightning. Each creature in that area makes a DC 16 Dexterity saving throw taking 44 (8d10) lightning damage on a failed save or half damage on a success. A creature that fails the save can't take reactions until the end of its next turn.