Acid Genasi (5e Subrace)
From D&D Wiki
Genasi are not always purely one of the four elements. Depending on the circumstances of their upbringing, they can "mutate" into new forms. One of the most common of these so-called para-genasi is the acid genasi, formed from a water genasi exposed to considerable amounts of lightning and electric charge.
Ability Score Increase. Your Dexterity score increases by 1.
Acid Resistance. You are resistant to Acid damage.
Acidic Flux. You know the Acid Spray cantrip. Once you reach 3rd level, you can cast Melf's Acid Arrow once with this trait, requiring no material components, and gain the ability to do so again once you finish a long rest. Constitution is your spellcasting ability for these spells.
Corrosive Strikes. Your unarmed strikes deal 1d4 Acid damage instead of the usual Bludgeoning damage.