Naga-Kin:Viper

As a Viper-Kin you're smaller and nimbler than your larger relatives. Viper-Kin are usually found in forests or deserts with ideologies such as "survival of the fittest" being the most common. Viper-Kin are usually 4ft-5ft tall. You occupy a 5ft x 5ft space or 1 hexagon.
Claws. When making an unarmed attack, your claws deal 1d4 Slashing damage.
Nerotoxin. As an action, you can bite a target as an unarmed strike, on hit the target takes 1d4 piercing and makes a constitution saving throw (DC 10+half your Class Level). On a failure they take 1d6 poison damage and are paralyzed. You may use this feat once per short or long rest.
(Also an option for players whos DM doesn't like large races. Remember to talk about what is wrong with being a large creature and if you should include the penalties of being a large creature represented in the Dungeon master's Guide)