Underdark Basilisk

Swamp

Gnoll Hunter

Pack tactics — Whenever Gnoll Hunter attacks, if you attacked with creatures with total power 6 or greater this combat, put a +1/+1 counter on Gnoll Hunter.

Lightfoot Rogue

Sneak Attack — Whenever Lightfoot Rogue attacks, roll a d20.
1—9 | Lightfoot Rogue gains deathtouch until end of turn.
10—19 | It gets +1/+0 and gains deathtouch until end of turn.
20 | It gets +3/+0 and gains first strike and deathtouch until end of turn.

Owlbear

Trample
Keen Senses — When Owlbear enters, draw a card.

Sepulcher Ghoul

Sacrifice another creature: Sepulcher Ghoul gets +2/+2 until end of turn. Activate only once each turn.

Ebondeath, Dracolich

Flash
Flying
Ebondeath, Dracolich enters tapped.
You may cast Ebondeath, Dracolich from your graveyard if a creature not named Ebondeath, Dracolich died this turn.

Shambling Ghast

When Shambling Ghast dies, choose one —
• Brave the Stench — Target creature an opponent controls gets -1/-1 until end of turn.
• Search the Body — Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Feign Death

Until end of turn, target creature gains "When this creature dies, return it to the battlefield tapped under its owner's control with a +1/+1 counter on it."

Precipitous Drop

Enchant creature
When Precipitous Drop enters, venture into the dungeon. (Enter the first room or advance to the next room.)
Enchanted creature gets -2/-2. It gets -5/-5 instead as long as you've completed a dungeon.

Black Dragon

Flying
Acid Breath — When Black Dragon enters, target creature an opponent controls gets -3/-3 until end of turn.

Circle of the Moon Druid

Bear Form — During your turn, Circle of the Moon Druid is a Bear with base power and toughness 4/2. (It loses all other creature types.)

Bulette

At the beginning of your end step, if a creature died this turn, put a +1/+1 counter on Bulette.

Vampire Spawn

When Vampire Spawn enters, each opponent loses 2 life and you gain 2 life.

Forest

Power Word Kill

Destroy target non-Angel, non-Demon, non-Devil, non-Dragon creature.

Yuan-Ti Fang-Blade

Deathtouch
Whenever Yuan-Ti Fang-Blade deals combat damage to a player, venture into the dungeon. (Enter the first room or advance to the next room.)

Grim Bounty

Destroy target creature or planeswalker. Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Purple Worm

This spell costs {2} less to cast if a creature died this turn.
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)