Lethargy Trap

If three or more creatures are attacking, you may pay {U} rather than pay this spell's mana cost.
Attacking creatures get -3/-0 until end of turn.

Permafrost Trap

If an opponent had a green creature enter the battlefield under their control this turn, you may pay {U} rather than pay this spell's mana cost.
Tap up to two target creatures. Those creatures don't untap during their controller's next untap step.

Cobra Trap

If a noncreature permanent under your control was destroyed this turn by a spell or ability an opponent controlled, you may pay {G} rather than pay this spell's mana cost.
Create four 1/1 green Snake creature tokens.

Kadena, Slinking Sorcerer

The first face-down creature spell you cast each turn costs {3} less to cast.
Whenever a face-down creature you control enters, draw a card.

Needlebite Trap

If an opponent gained life this turn, you may pay {B} rather than pay this spell's mana cost.
Target player loses 5 life and you gain 5 life.

Saw It Coming

Counter target spell.
Foretell {1}{U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Poison the Cup

Destroy target creature. If this spell was foretold, scry 2.
Foretell {1}{B} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Slingbow Trap

If a black creature with flying is attacking, you may pay {G} rather than pay this spell's mana cost.
Destroy target attacking creature with flying.

Whiplash Trap

If an opponent had two or more creatures enter the battlefield under their control this turn, you may pay {U} rather than pay this spell's mana cost.
Return two target creatures to their owners' hands.

Archive Trap

If an opponent searched their library this turn, you may pay {0} rather than pay this spell's mana cost.
Target opponent mills thirteen cards.

Pit Trap

{2}, {T}, Sacrifice this artifact: Destroy target attacking creature without flying. It can't be regenerated.

Mindbreak Trap

If an opponent cast three or more spells this turn, you may pay {0} rather than pay this spell's mana cost.
Exile any number of target spells.

Booby Trap

As this artifact enters, choose an opponent and a card name other than a basic land card name.
The chosen player reveals each card they draw.
When the chosen player draws a card with the chosen name, sacrifice this artifact. If you do, this artifact deals 10 damage to that player.

Nemesis Trap

If a white creature is attacking, you may pay {B}{B} rather than pay this spell's mana cost.
Exile target attacking creature. Create a token that's a copy of that creature. Exile it at the beginning of the next end step.

Summoning Trap

If a creature spell you cast this turn was countered by a spell or ability an opponent controlled, you may pay {0} rather than pay this spell's mana cost.
Look at the top seven cards of your library. You may put a creature card from among them onto the battlefield. Put the rest on the bottom of your library in any order.

Ravenous Trap

If an opponent had three or more cards put into their graveyard from anywhere this turn, you may pay {0} rather than pay this spell's mana cost.
Exile target player's graveyard.

Baloth Cage Trap

If an opponent had an artifact enter the battlefield under their control this turn, you may pay {1}{G} rather than pay this spell's mana cost.
Create a 4/4 green Beast creature token.