race features:
Keen Smell. Thanks to your origin, you have advantage on Wisdom (Perception), Wisdom (Survival), and Intelligence (Investigation) checks that involve smell.
Pack Tactics. You have advantage on an attack roll against a creature if at least one of your allies is within 5 feet of the creature and the ally isn't incapacitated.
Bite. Your fanged maw is a natural weapon, which you can use to make unarmed strikes. If you hit with it, you deal piercing damage equal to 1d6 + your Strength modifier, instead of the bludgeoning damage normal for an unarmed strike.
Rampage. When you reduce a creature to 0 hit points with a melee attack on your turn, you can take a bonus action to move up to half your speed and make a bite attack.
Hyena Origin. You have advantage on charisma checks to interact with hyenas.
Gnolls were extremely tall, with the average member of the race standing on average between 7′0″‒7′6″. Though gnolls were relatively lean for their height, weighing in usually between 280‒320 lb, they cut an impressive visage.