If you're interested in building a deck which uses Poison for damage, Deadly Poison can be a good Act 1 pickup. It usually won't make the cut later on, and if you're not attached to the Poison idea, there are probably better other Act 1 choices for damage that you can find.
Baalorlord
The quintessential first-floor poison card. This is better damage than similar attacks as long as the fight lasts for more than 3 turns, which is the case for most boss and elite fights.
