http://www.wizards.com/Magic/Magazine/Article.aspx?x=mtg/daily/arcana/981

Make sure you work up an appetite before playing the "Primordial Hunger" deck, because it's feeding time! Many of the creatures in your deck have the devour ability: As one of them enters the battlefield, you can sacrifice any number of your other creatures to grow the new creature to gigantic proportions. For example, if you sacrifice three creatures as Thunder-Thrash Elder enters the battlefield, it'll be a 10/10… and if you sacrifice five creatures as Thromok the Insatiable enters the battlefield, it'll be a 25/25!

The deck's secret weapon is that its creatures without devour want to get eaten! Some of them, like Nest Invader and Beetleback Chief, enter the battlefield with expendable (and delicious) friends in tow. Others provide benefits when they die: Mudbutton Torchrunner deals damage, Viridian Emissary gives you a land, and Brindle Shoat leaves behind a creature token that's bigger than it was. Best of all, if you can't find a timely devour creature, Overrun or Hellion Eruption can let the little creatures rise up and conquer all on their own.

Many of the cards in your planar deck supercharge your strategies. Selesnya Loft Gardens doubles your token production and your +1/+1 counter generation, and you've got plenty of both. Lair of the Ashen Idol forces each player to sacrifice creatures, which you're handily prepared for… but are your opponents? And Jund grants devour 5 to each creature spell you cast, which upgrades the ones that already have devour while turning all the others into ravenous predators in their own right.