Cerberus Pup

Keen Hearing and Smell. The wolf has advantage on Wisdom (Perception) checks that rely on hearing or smell.

Pack Tactics. The wolf has advantage on an attack roll against a creature if at least one of the wolf's allies is within 5 feet of the creature and the ally isn't incapacitated.

Three Headed. this creature has 3 attack actions each attack must come from a different head.

Caustic Spittle. the first bite attack per turn deals an additional 1d6 acid damage

Searing Spittle. the second bite attack per turn deals an additional 1d6 fire damage

Poisonous Spittle. the third bite attack per turn deals an additional 1d6 poison damage

Its a puppy. all attacks have disadvantage on it as well as all animal handling checks have advantage against it.

Bite. 1d4 Damage

Flea. The pup disengages and can run double its movement speed.

Brimstone Belch. A 15ft-by-15ft smoke cloud erupts from its maws. if a player turn is ended in smoke the victim is poisoned and blinded until they exit, or it dissipates             (2 turns)

Bark. This either charms or frightens an enemy wisdom saving throw 10.