Guilds of Ravnica

Bounty Agent | Creature | Human Soldier | Vigilance {T}, Sacrifice Bounty Agent: Destroy target legendary permanent that's an artifact, creature, or enchantment. | Randy Vargas

Narcomoeba | Creature | Illusion | Flying When Narcomoeba is put into your graveyard from your library, you may put it onto the battlefield. | Howard Lyon

Runaway Steam-Kin | Creature | Elemental | Whenever you cast a red spell, if Runaway Steam-Kin has fewer than three +1/+1 counters on it, put a +1/+1 counter on Runaway Steam-Kin. Remove three +1/+1 counters from Runaway Steam-Kin: Add {R}{R}{R}. | Jason Felix

Swiftblade Vindicator | Creature | Human Soldier | Double strike, vigilance, trample | Viktor Titov

Emmara, Soul of the Accord | Legendary Creature | Elf Cleric | Whenever Emmara, Soul of the Accord becomes tapped, create a 1/1 white Soldier creature token with lifelink. | Mark Winters