Young Cave Dragon

The cave dragon can burrow through solid rock at half its burrowing speed and leaves a 10-foot wide, 5-foot high tunnel in its wake.

The dragon's innate spellcasting ability is Charisma (spell save DC 15). It can innately cast the following spells, requiring no material components:

• 1/day each: blur, counterspell, web
• 3/day: darkness

The dragon makes three attacks; one with its biteand two with its claws.

Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 13 (2d6 + 6) piercing damage plus 3 (1d6) poison damage.

Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 13 (2d6 + 6) slashing damage.

The dragon exhales a cone of black poison gas in a 30-foot cone. Each creature in that area must make a DC 16 Constitution saving throw, taking 45 (13d6) poison damage on a failed save and becoming poisoned if it is a creature. The poisoned condition lasts until the target takes a long or short rest or removes the condition with lesser restoration or comparable magic. If the save is successful, the target takes half damage and is not poisoned.

D5

When a creature tries to enter a space adjacent to a cave dragon, the dragon flares its many feelers and spikes. The creature cannot enter a space adjacent to the dragon unless it makes a successful DC 16 Dexterity saving throw. If the saving throw fails, the creature can keep moving but only into spaces that aren't within 5 feet of the dragon and takes 4 (1d8) piercing damage from spikes.