River Boa

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
{G}: Regenerate River Boa.

Wall of Corpses

Defender (This creature can't attack.)
{B}, Sacrifice Wall of Corpses: Destroy target creature Wall of Corpses is blocking.

Spore Cloud

Tap all blocking creatures. Prevent all combat damage that would be dealt this turn. Each attacking creature and each blocking creature doesn't untap during its controller's next untap step.

Venom

Enchant creature
Whenever enchanted creature blocks or becomes blocked by a non-Wall creature, destroy the other creature at end of combat.

Lure

Enchant creature
All creatures able to block enchanted creature do so.

Pit Scorpion

Whenever Pit Scorpion deals damage to a player, that player gets a poison counter. (A player with ten or more poison counters loses the game.)

Runed Arch

Runed Arch enters the battlefield tapped.
{X}, {T}, Sacrifice Runed Arch: X target creatures with power 2 or less can't be blocked this turn.

Swamp Mosquito

Flying
Whenever Swamp Mosquito attacks and isn't blocked, defending player gets a poison counter. (A player with ten or more poison counters loses the game.)

Everglades

Everglades enters the battlefield tapped.
When Everglades enters the battlefield, sacrifice it unless you return an untapped Swamp you control to its owner's hand.
{T}: Add {C}{B}.

Aegis of the Meek

{1}, {T}: Target 1/1 creature gets +1/+2 until end of turn.

Forest

Crypt Cobra

Whenever Crypt Cobra attacks and isn't blocked, defending player gets a poison counter. (A player with ten or more poison counters loses the game.)

Marsh Viper

Whenever Marsh Viper deals damage to a player, that player gets two poison counters. (A player with ten or more poison counters loses the game.)

Cadaverous Knight

Flanking (Whenever a creature without flanking blocks this creature, the blocking creature gets -1/-1 until end of turn.)
{1}{B}{B}: Regenerate Cadaverous Knight.

Serpent Generator

{4}, {T}: Create a 1/1 colorless Snake artifact creature token. It has "Whenever this creature deals damage to a player, that player gets a poison counter." (A player with ten or more poison counters loses the game.)

Swamp

Jangling Automaton

Whenever Jangling Automaton attacks, untap all creatures defending player controls.

Jungle Basin

Jungle Basin enters the battlefield tapped.
When Jungle Basin enters the battlefield, sacrifice it unless you return an untapped Forest you control to its owner's hand.
{T}: Add {C}{G}.

Suq'Ata Assassin

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)
Whenever Suq'Ata Assassin attacks and isn't blocked, defending player gets a poison counter. (A player with ten or more poison counters loses the game.)

Sabertooth Cobra

Whenever Sabertooth Cobra deals damage to a player, that player gets a poison counter. The player gets another poison counter at the beginning of their next upkeep unless they pay {2} before that step. (A player with ten or more poison counters loses the game.)