
Nightfire Giant | Creature | Zombie Giant | Nightfire Giant gets +1/+1 as long as you control a Mountain.
{4}{R}: Nightfire Giant deals 2 damage to any target. | Dave Kendall

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

Belligerent Sliver | Creature | Sliver | Sliver creatures you control have menace. (They can't be blocked except by two or more creatures.) | Raymond Swanland

Brood Keeper | Creature | Human Shaman | Whenever an Aura becomes attached to Brood Keeper, create a 2/2 red Dragon creature token with flying. It has "{R}: This creature gets +1/+0 until end of turn." | Scott Murphy

Frenzied Goblin | Creature | Goblin Berserker | Whenever Frenzied Goblin attacks, you may pay {R}. If you do, target creature can't block this turn. | Carl Critchlow

Kird Chieftain | Creature | Ape | Kird Chieftain gets +1/+1 as long as you control a Forest.
{4}{G}: Target creature gets +2/+2 and gains trample until end of turn. (It can deal excess combat damage to the player or planeswalker it's attacking.) | Lars Grant-West

Paragon of Fierce Defiance | Creature | Human Warrior | Other red creatures you control get +1/+1.
{R}, {T}: Another target red creature you control gains haste until end of turn. (It can attack and {T} this turn.) | Slawomir Maniak