Not only do you draw a card, but you can immediately cast a spell from your hand with mana value equal to or less than the damage dealt, without paying its cost
Krakens in MTG aren't always giant squids or octopi, and some are just giant nondescript, quasi-dinosaurian, quasi-serpentine beasts like this guy
When Ertai Resurrected enters, choose up to one Counter target spell, activated ability, or triggered ability
You can also check out the same details in a CubeCobra.com presentation, where hovering over any card will show you a near-mint version
A particularly notable example of this is the famous Shadowless Base Set Charizard the card that reignited the recent boom of the TCG sells for hundreds of thousands at auction, but there are plenty of cards out there that are rarer
By using a Supporter such as Felicitys Drawing to discard Energy, and then using Sacrifice to attach the Energy to Regigigas, you could get him set-up by turn two or three