Bog Raiders

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

Ultimate Price

Quag Vampires

Multikicker {1}{B} (You may pay an additional {1}{B} any number of times as you cast this spell.)
Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
Quag Vampires enters with a +1/+1 counter on it for each time it was kicked.

Poison the Well

Destroy target land. Poison the Well deals 2 damage to that land's controller.

Stalker Hag

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

Doom Blade

Swamp

Bog Wraith

Helldozer

{B}{B}{B}, {T}: Destroy target land. If that land was nonbasic, untap Helldozer.

Blistergrub

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)
When Blistergrub dies, each opponent loses 2 life.

Destroy the Evidence

Destroy target land. Its controller reveals cards from the top of their library until they reveal a land card, then puts those cards into their graveyard.

Plague Beetle

Drain the Well

Contaminated Ground

Enchant land
Enchanted land is a Swamp.
Whenever enchanted land becomes tapped, its controller loses 2 life.