Homebrew
Pack Leader. Allies within 30 ft. of Adarogg gain advantage on melee attack rolls if adjacent to the same enemy.
Lava Blood. When a creature hits Adarogg with a melee weapon attack, the attacker takes 1d10 fire damage.
Legendary Resistance (2/Day). If Adarogg fails a saving throw, he can choose to succeed instead.
Multiattack. Adarogg makes two Bite attacks. Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 2d8+6 piercing damage plus 2d6 fire damage. Molten Breath (Recharge 5–6). Adarogg exhales flame in a 30-foot cone. Each creature in the area must make a DC 15 Dexterity saving throw, taking 8d8 fire damage on a failed save, or half as much on a success. Seismic Pounce (Recharge 6). Adarogg leaps up to 30 ft to a space within 5 ft of a creature. Each creature within 10 ft. of the landing space must make a DC 14 Strength saving throw or take 4d6 bludgeoning damage and be knocked prone.
Adarogg can take 2 legendary actions, choosing from the options below. Only one legendary action can be used at a time and only at the end of another creature’s turn. Burning Snap. Adarogg makes one Bite attack. Scorching Roar. Each creature within 10 feet must succeed on a DC 13 Wisdom saving throw or be frightened until the end of their next turn.
On initiative count 20 (losing ties), Adarogg can take one lair action: