Bog Wraith

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)

Raise Dead

Return target creature card from your graveyard to your hand.

Weakness

Enchant creature
Enchanted creature gets -2/-1.

Lord of the Pit

Flying, trample
At the beginning of your upkeep, sacrifice a creature other than Lord of the Pit. If you can't, Lord of the Pit deals 7 damage to you.

Nightmare

Flying (This creature can't be blocked except by creatures with flying or reach.)
Nightmare's power and toughness are each equal to the number of Swamps you control.

Drudge Skeletons

{B}: Regenerate Drudge Skeletons. (The next time this creature would be destroyed this turn, instead tap it, remove it from combat, and heal all damage on it.)

Swamp

Zombie Master

Other Zombie creatures have swampwalk. (They can't be blocked as long as defending player controls a Swamp.)
Other Zombies have "{B}: Regenerate this permanent."

Evil Presence

Scathe Zombies

Bad Moon

Terror

Destroy target nonartifact, nonblack creature. It can't be regenerated.

Throne of Bone

Whenever a player casts a black spell, you may pay {1}. If you do, you gain 1 life.