Homebrew
You have draconic breath that pulls from poisonous and petrifying nature of a stone dragon. You can use your action to exhale a poisonous gas that slows all who breaths it in. In a 15ft cone each creature in that area must make a Constitution saving throw (DC = 8 + your Constitution modifier + your proficiency bonus). A creature takes 1d10 poison damage and reduce their speed by half on a failed save, or half as much damage on a successful one. The damage increases to 2d10 at 6th level, 3d10 at 11th level, and 4d10 at 16th level. After you use your tidal breath, you can’t use it again until you complete a short or long rest.
You have resistance to poison and piercing damage.
Starting at 5th level, as an action, you can channel your draconic energy to protect yourself. For 1 minute, you become immune to poison damage. Once you use this trait, you can’t do so again until you finish a long rest.
When you use your movement in your turn everyone within 5 feet of you that you move past must make a Dexterity saving throw (DC = 8 + Strength modifier + proficiency bonus) or fall prone.