Bonezy

Multi attack : You may use two claw attacks and one bite attack  or one bite, and tail

Claws Melee Weapon Attack: +6 to hit, reach 5ft., one target. Hit: (2d6 + 6) Slashing damage.

Bite melee weapon attack: +6 to hit, reach 10ft  one target.   hit: (2d10 +6) piercing 

Tail  melee weapon attack: +6 to hit, reach 15ft  one target.    Hit: (2d8 +6) piercing

Explosive oil Breath   1 use per short rest, during short rest you refill and prepare the next breath

The dragon exhales a burning substance in a 45-foot line that is 10 feet wide.  Each creature in that line must make a DC 17 Dexterity saving throw.  On a failed save, the target is adhered to by the substance. This substance can only be removed by a tube of Universal solvent

A target adhered to by the substance takes 22 (4d10) fire damage immediately and 22 (4d10) fire damage at the end of its next turn.  At the end of the target's second turn after failing its saving throw, the substance explodes in a 15-foot radius sphere centered on the target.  Each creature within 15 feet of the target must succeed on a DC 23 Dexterity saving throw.  The target and each creature that fails its saving throw takes 44 (8d10) fire damage, or half as much damage on a successful save.  A creature in the area of more than one explosion is affected only once.

Being underwater doesn't grant resistance against damage dealt by the substance.  The substance explodes immediately if it comes in contact with water.