It is very important when creating a new race that it not be the overwhelming best possible race for certain classes. Being able to get free movement and a free melee attack every single time you down an opponent it WAY too good of a bonus to give a Barbarian. Especially at lower levels when d6+Str bonus actually means something.

Speaking of which, the natural attack should only be d4, not d6. Again-- it doesn't matter what the MM says, it matters what is balanced for PCs. And so far all PC races that have natural attack have it at d4-- its what you would get as a level 1 monk.

The natural attack is a direct copy/paste word for word of the Lizardfolk's bite attack, without a single thing changed, from Volo's Guide to Monsters. It is an official race made by Wizards of the Coast in a published book, so I assume it was playtested thoroughly before release and it's bite attack was considered balanced.

The MM entry is all about giving the creature some sort of ability that is meant to counter the fact that they get no class abilities-- plus they want the creatures to fight like those stated creatures. But if you are giving them class abilities, you should be less focused on how to give the race extra damage and movement every round and instead consider how to give them interesting options.

Instead of half-movement, maybe make it an option 5' step into the square previously occupied by the target that was reduced to 0 HPs.

The ability can best be described as the Orc's Aggression and the Lizardfolk's Hungry Jaws ability, but less movement, and no THP. In addition it must be down, by you, with a melee attack. It's not going to be happening every single round, unless you are somehow last hitting every enemy you touch. It is also the most iconic thing that Gnolls really have in 5e.

Also-- no race should be granting more than one bonus skill. I am sure there already are ones that do, but it should be avoided. It would be best if every race granted 1 and only 1 bonus skill, but 2 skills stacked into a race just because you can't think of anything else to give them is too much.

There just aren't that many skills in the game and if one player be proficient with nearly half the skills in the game because their race gave them 2, their background gave them 2 and their class gave them 5... well, it means there is less chance any of the other players are going to be proficient in skills this character doesn't have any have their opportunity to shine.

4 races of my count give proficiency in 2 skills: Half-Elf, Kenku, Lizardfolk and Tabaxi. Two of these races give an option of two skills out of a choice of 4. However, I don't mind removing Perception because the lore reason for it is possibly a little contrived, although I feel Gnolls do have good sense. Intimidation makes the most sense to keep, however.

And bow proficiency? Look, I get that some silly things were written in 4E, but these 7+' tall more animal than man creatures should not be universally expert with bows. I think that was just an excuse to match them up with the Ranger class which naturally had a heavy emphasis on bows. Also, it is kind of silly to give the same race both a natural attack AND weapon proficiency.

The weapon proficiency is from the lore in Volo's guide to monsters. It says they always attack from range, when they can, to soften enemies up before going in for the kill. In addition in 4e and 5e it mentions they scavenge weapons and armor from their kills. It made sense, and it's only 3 proficiency. Elves and Dwarves get 4 weapon proficiency, as does any race that gets a weapon proficiency.

And for the attribute.... Sure... +2 Con with a +1 in either Dexterity or Constitution would be fair. Honestly, I think the races that have subraces are eventually going to be filled out so you can have that floating +1 in any attribute. It would probably be better if all races just allowed you to stick that +1 in any score other than the one you get a +2 in as it would increase the number of viable classes for any given race.

I was considering a whole sale change to +2 Str, +1 Cha but I'm almost definitely changing the Dex bonus. Gnolls favor strength over all.

That said they have no resistances, no free spells, no extra movement such a flight, swimming, climbing or teleporting, they don't get any particularly powerful abilities, no environmental boons such as holding breath, breathing air/water, etc.

They're pretty barebones. They really get a bite, a proficiency in a skill (or two), 3 ranged weapons on a strength based character, (similar to dwarves who do not get strength as base, and elves who get a lot of swords) and a rare trigger to move and make a free attack. I nerfed their base movement to 30. I removed pack tactics. They have darkvision but I'd say a majority of races do.

They're probably exactly middle of the pack as is, less if I remove perception proficiency. Bugbears get Sneak Attack *lite* and Aasimar get paladin damage auras *lite*, etc.

I would say they're about equal to Tabaxi - Darkvision, natural weapon, two skills, a movement bonus on melee kill as a bonus action (if you've already used your bonus action you can't use the racial, so does not stack well with TWF, or Monks or Barbarian rage, etc.) as opposed to just a movement on bonus action. I can remove the weapon proficiency. Lizardfolk don't get them either, but they can craft them. Lizardfolk do get natural AC though.

ASI +3 = 12
Common, +1 Language = 0
Skill Proficiency = 4
Speed 30 = 0
Darkvision 60 = 3
1d6 natural weapon = 2
weapon's training = 1
Rampage = 5

Total = 27

If I removed Perception it'd be 25, the Rampage score was generated from the Orc's +3 Aggresion and Lizardfolk's +2 Hungry Jaws.

This is right around the score for: Hill Dwarf, Mountain Dwarf, High Elf, Wood Elf, Drow, Half-Elf, Aarakocra, Aasimar Protector, Aasimar Scourge, Aasimar Fallen, Furbolg, Lizardfolk and Triton. I'd say it's in good company.

Score Generated by:

With the Musicus score it'd be:
ASI = 3
Darkvision = 0.5
Natural Weapon = 1
Skills = 1
Weapon Training = 0.5
Rampage = 1

Musicus score is 7. Pretty strong. The same as Dwarves and Elves.