Young Blue Dragon

5e compatible shield

Large dragon, lawful evil

Armor Class 18 (natural armor)
Hit Points 152 (16d10 + 64)
Speed 40 ft., burrow 20 ft., fly 80 ft.

STR DEX CON INT WIS CHA
21 (+5) 10 (+0) 19 (+4) 14 (+2) 13 (+1) 17 (+3)

Saving Throws Dex +4, Con +8, Wis +5, Cha +7
Skills Perception +9, Stealth +4
Damage Resistances 
Damage Immunities lightning
Condition Immunities 
Senses blindsight 30 ft., darkvision 120 ft., passive Perception 19
Languages Common, Draconic
Challenge 9 (5000 XP)

Actions

Multiattack. The dragon makes three attacks: one with its bite and two with its claws.

Bite. Melee Weapon Attack: +9 to hit, reach 10 ft., one target. Hit: 16 (2d10 + 5) piercing damage plus 5 (1d10) lightning damage.

Claw. Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit: 12 (2d6 + 5) slashing damage.

Lightning Breath (Recharge 5–6). The dragon exhales lightning in an 60-foot line that is 5 feet wide. Each creature in that line must make a DC 16 Dexterity saving throw, taking 55 (10d10) lightning damage on a failed save, or half as much damage on a successful one.