Frost Lynx

When Frost Lynx enters, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

Piercing Rays

Exile target tapped creature.
Forecast — {2}{W}, Reveal Piercing Rays from your hand: Tap target untapped creature. (Activate this ability only during your upkeep and only once each turn.)

Kytheon's Irregulars

Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)
{W}{W}: Tap target creature.

Chillbringer

Flying
When Chillbringer enters, tap target creature an opponent controls. It doesn't untap during its controller's next untap step.

Frost Trickster

Flying
When Frost Trickster enters, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

Guardian of Tazeem

Flying
Landfall — Whenever a land you control enters, tap target creature an opponent controls. If that land is an Island, that creature doesn't untap during its controller's next untap step.

Sleep of the Dead

Tap target creature. It doesn't untap during its controller's next untap step.
Escape—{2}{U}, Exile three other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Island

Borrowing 100,000 Arrows

Draw a card for each tapped creature target opponent controls.

Code of Constraint

Target creature gets -4/-0 until end of turn.
Draw a card.
Addendum — If you cast this spell during your main phase, tap that creature and it doesn't untap during its controller's next untap step.

Tranquil Cove

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {W} or {U}.

Verity Circle

Whenever a creature an opponent controls becomes tapped, if it isn't being declared as an attacker, you may draw a card.
{4}{U}: Tap target creature without flying.

Sleeper Dart

When Sleeper Dart enters, draw a card.
{T}, Sacrifice Sleeper Dart: Target creature doesn't untap during its controller's next untap step.