Wall of Frost

Creature - Wall 0/7, 1UU (3)
Defender (This creature can't attack.)

Whenever Wall of Frost blocks a creature, that creature doesn't untap during its controller's next untap step.
"I welcome it. The pasture is cleared of weeds and the wolves are frozen solid."
-Lumi, goatherd
Illus. Mike Bierek

Gatherer Card Rulings [Nov 2009]

• 10/1/2009: Unlike Sleep, Wall of Frost's triggered ability tracks the creature, but not its controller. If the creature changes controllers before its first controller's next untap step has come around, then it won't untap during its new controller's next untap step.

Format Legality	Legal in Vintage, Legacy, Extended, Standard, MTGO Classic
Printings (1/9)	Magic 2010 (Uncommon)