Chest was added in Beta 30.0. Previous Versions can be found here.
Chest functions like a small Script Bomb, able to let you draw 2 cards when it dies (but without any benefits regarding specific cards). Unlike Script Bomb however, it draws through a Dust instead of a Turn start sacrifice, so you will always draw those cards unless it dies while Silenced. It also doesn't die automatically when your turn starts. But due to its 3 HP, it's also not easily killed by yourself on its first turn.
This card can work most in a heavy draw deck like some Bravery ones.