Cheapest priced copy (Magic 2014): $0.49 at Card Kingdom, near mint, their price list as of .
Garruk's Horde 
Creature — Beast · 7/7 · Rare · Magic 2012 · #176
Trample
Play with the top card of your library revealed.
You may cast creature spells from the top of your library. (Do this only any time you could cast that creature spell. You still pay the spell's costs.)
Legal inCommanderPioneerModernLegacyVintage
Not legal inBrawlStandardPauper
4 printings · $0.49 to $0.79 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Magic 2012 | 176 | Rare | $0.59 | $0.79 |
| Magic 2014 | 173 | Rare | $0.49 | $0.49 |
| Magic 2012 Promos | 176★ | Rare | — | $0.79 |
| Welcome Deck 2017 | 24 | Rare | $0.59 | — |
6 rulings from Wizards of the Coast
- 22 September 2011If the top card of your library is Dryad Arbor (the only card that’s both a creature and a land), you can’t play it this way. Dryad Arbor can’t be cast as a spell.
- 22 September 2011Normally, Garruk’s Horde allows you to cast the top card of your library if it’s a creature card, it’s your main phase, and the stack is empty. If that creature card has flash, you’ll be able to cast it at the time you could cast an instant, even on an opponent’s turn.
- 22 September 2011You’ll still pay all costs for that spell, including additional costs. You may also pay alternative costs.
- 15 April 2013The top card of your library isn’t in your hand, so you can’t suspend it, cycle it, discard it, or activate any of its activated abilities.
- 15 April 2013When playing with the top card of your library revealed, if an effect tells you to draw several cards, reveal each one before you draw it.
- 15 April 2013If the top card of your library changes while you’re casting a spell, playing a land, or activating an ability, the new top card won’t be revealed until you finish doing so.