Vorsorus The Young Black Dragon

Actions

Multiattack - The dragon makes two attacks: one with its bite and the other with its claw or both with its claws   Bite - Melee Weapon Attack: +4 to hit, reach 10 ft., one target. Hit - 9 (1d10 + 4) 1d10+4 piercing damage plus 4 (1d8) 1d8 acid damage.   Claw - Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit - 9 (2d4 + 4) 2d4+4 slashing damage.   Acid Breath (Recharge 5-6) - the dragon exhales acid in a 25 ft. line. Each creature within that area must make a DC 13 constitution saving throw, taking 25 (5d10) 5d10 poison damage on a failed save, or half as much damage on a successful one.

Vorsorus is worshipped by a clan of kobolds, which constantly bring him treasures which he bathes in, or else he chooses a victim from the clan and devours them whole as an example to rest of the kobolds. He lives underneath the Lake of The Helm, located in The Triplici Point. His lair is a wild and twisted maze of damp stone tunnels, some being completely submerged. It is easy to get lost in that thicket of passages...

Regional Effects

- Land within 6 miles of the lair takes twice as long to traverse, as the vegetation grows abnormally thick, twisting around everything in the vicinity.  

Your classic black dragon, look at Black Dragon description on Pg. 89 of the D&D 5E monster manual.

Swamps and forests