Prevent all combat damage that would be dealt this turn.

Jungle Basin

This land enters tapped.
When this land enters, sacrifice it unless you return an untapped Forest you control to its owner's hand.
{T}: Add {C}{G}.

Crypt Cobra

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

Aegis of the Meek

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

Wall of Corpses

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

Swamp Mosquito

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

River Boa

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

Jangling Automaton

Whenever this creature attacks, untap all creatures defending player controls.

Marsh Viper

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

Sabertooth Cobra

Whenever this creature 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.)

Runed Arch

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

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.

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.)

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 this creature.

Forest

Pit Scorpion

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.)

Suq'Ata Assassin

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

Everglades

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

Swamp

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.