Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Burning-Tree Emissary

When Burning-Tree Emissary enters, add {R}{G}.

Goblin Shortcutter

When Goblin Shortcutter enters, target creature can't block this turn.

Rancor

Enchant creature
Enchanted creature gets +2/+0 and has trample.
When Rancor is put into a graveyard from the battlefield, return Rancor to its owner's hand.

Rogue Elephant

When Rogue Elephant enters, sacrifice it unless you sacrifice a Forest.

Kird Ape

Kird Ape gets +1/+2 as long as you control a Forest.

Keldon Marauders

Vanishing 2 (This creature enters with two time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
When Keldon Marauders enters or leaves the battlefield, it deals 1 damage to target player or planeswalker.