It's very easy to underestimate how much damage Snakebite does because there's no other card which reliably applies this much Poison to a single target in the game. Every other way to apply 7+ Poison is conditional or slower. I expect one upgraded copy to deal about 100 damage to an Act 1 Boss, played twice in the fight. It ALSO has retain! Obscene card. Comparable damage to Noxious Fumes, often slightly faster. Also obscene w/ Bullet Time, Pounce, Flechettes...
