Dude... (unlocks Kiki-Jiki, Mirror-Breaker)
In dude, your deck can have only creatures. (not even land, except dryad arbor)
There aren't many things to try for this one, since the only available mana sources are 4x
Dryad Arbor, 4x
Elvish Spirit Guide, and 4x
Simian Spirit Guide. That leaves green or red as the core of the deck, or artifacts, like maybe affinity, which I tried, but it didn't work.
So, like probably everyone else, I made an Elf deck. I tinkered around with a few ideas, including
Elves of Deep Shadow and splashing black for things like
Dark Confidant or
Shriekmaw, but I found that 1) if you can actually cast dark confidant, you've already won most games, 2) shriekmaw sucks balls against zombies and rats, and again, if you can cast it, it means you've got a decent board presence already. I'd advise against doing this. Splashing the simian as colourless mana might work, but since you'd still need an arbor or elvish spirit guide, I didn't bother using him.
The final list I used:
.1913 4
Dryad Arbor.1892 4
Elvish Spirit Guide.1934 4
Heritage Druid.149 4
Llanowar Elves.1293 4
Fyndhorn Elves.1974 4
Priest of Titania.1816 4
Wirewood Symbiote.1360 4
Wren's Run Vanquisher.1461 4
Imperious Perfect.1564 4
Elvish Archdruid.1942 4
Regal Force.1997 4
Birchlore Rangers*
.15 4
Birds of Paradise.1939 4
Nettle Sentinel.1308 4
Platinum AngelI'd wager that the only surprises here are
Platinum Angel and maybe
Wirewood Symbiote (which wins MVP this round). The angel is autowin most of the time, and it provides insurance against enemy flyers, which basically instantly defeat this deck.
Strategy: mull until you have dryad arbor (preferably) or elvish spirit guide, and hopefully any one-mana dude that makes mana himself. Get out any one-drop mana producer (use spirit guide even if you have arbor first turn too) and play
Priest of Titania as soon as you can. Also remember to play things in the right order; for instance, playing one mana elves before tapping
Priest of Titania (or elvish archdruid) translates into those elves being zero cost. The deck plays just like a typical elf deck, only you mulligan a lot more :p
Wirewood Symbiote deserves special mention. He can make oodles of mana by bouncing a tapped elf to untap a Priest or Archdruid. He can save your elves from death by bouncing them before they die. You can also make suicide runs with
Wren's Run Vanquisher, then bounce him before combat damage is assigned, and all defenders will die from the venom effect. He can even let you make extra warriors with
Imperious Perfect. For all these reasons, plus costing only G to play, he wins MVP for this deck

(imagine if he was subtype elf instead of insect...)
The hardest matchups are slivers, (winged sliver, plus it's really fast and has counters to boot) goblins, (piledriver and haste-giving lords), though the shadow deck and zombies can be troublesome, too. Turbofog is tougher, but can be beaten (I didn't see it much with this deck, and not at all in the winning gauntlet). Soldiers, kithkin, elves (both), merfolk, grow, and rats usually lose if you didn't mull yourself away.
The winning gauntlet went against shadow, zombies, elves, rats, merfolk, soldiers, kithkin, slivers, burn, (those 9 not necessarily in that order) and then goblins in the last round, which scared the crap out of me, but he didn't drop a lord on turn 3 for his piledriver/prospector on the board, and I dropped
Regal Force and
Platinum Angel the turn after I would have died if he'd had a turn 3 chieftain/warchief :p
That leaves super mulligan and land ho. My land ho deck probably looks just like everyone else's, only I made it about 75-80 cards so that it can beat turbofog more consistently, and my super mulligan deck keeps changing, but usually its weenie or burn/removal.
I'll have to watch that thing about knowing the order of the first cards in super mulligan; that will be handy, and you could even take mulligans just to 'peek' at your top few cards until you like what you see, since your hand is zero cards anyway. An oath deck might be great when you can mull and ensure you'll get one in time!