Mindvenom Viper

Hexproof
Whenever Mindvenom Viper deals combat damage to a player, you may draw a card.
As long as Mindvenom Viper is green, it loses hexproof, gets +2/+2, and has deathtouch.
Manashift {3}{g}{g} (You may cast this spell for its manashift cost. If you do, it becomes green and loses all other colors.)