
Ajani's Pridemate | Creature | Cat Soldier | Whenever you gain life, put a +1/+1 counter on Ajani's Pridemate. | Svetlin Velinov

Dauntless River Marshal | Creature | Human Soldier | Dauntless River Marshal gets +1/+1 as long as you control an Island.
{3}{U}: Tap target creature. | Mark Winters

Wall of Essence | Creature | Wall | Defender (This creature can't attack.)
Whenever Wall of Essence is dealt combat damage, you gain that much life. | Adam Rex

Diffusion Sliver | Creature | Sliver | Whenever a Sliver creature you control becomes the target of a spell or ability an opponent controls, counter that spell or ability unless its controller pays {2}. | Trevor Claxton

Quickling | Creature | Faerie Rogue | Flash (You may cast this spell any time you could cast an instant.)
Flying
When Quickling enters the battlefield, sacrifice it unless you return another creature you control to its owner's hand. | Clint Cearley

Leeching Sliver | Creature | Sliver | Whenever a Sliver you control attacks, defending player loses 1 life. | Svetlin Velinov

Altac Bloodseeker | Creature | Human Berserker | Whenever a creature an opponent controls dies, Altac Bloodseeker gets +2/+0 and gains first strike and haste until end of turn. (It deals combat damage before creatures without first strike, and it can attack and {T} as soon as it comes under your control.) | Cynthia Sheppard

Venom Sliver | Creature | Sliver | Sliver creatures you control have deathtouch. (Any amount of damage a creature with deathtouch deals to a creature is enough to destroy it.) | Dave Kendall

Wall of Mulch | Creature | Wall | Defender (This creature can't attack.)
{G}, Sacrifice a Wall: Draw a card. | Anthony S. Waters