Ice Floe

• WWizards of the Coast2008-10-01
  Official Ruling
  If the ability resolves, then the creature gains flying later, Ice Floe’s effect will not end. (The ability checks whether the creature has flying only at the time you activate it and the time it resolves.)
• WWizards of the Coast2008-10-01
  Official Ruling
  If the affected creature is untapped by some other spell or ability, Ice Floe’s effect will not end. If you keep Ice Floe tapped, and that creature becomes tapped again, Ice Floe will continue to prevent it from being untapped during its controller’s untap step.
• WWizards of the Coast2008-10-01
  Official Ruling
  If Ice Floe untaps or leaves the battlefield, its effect will end. This has no immediate visible affect on the creature. (It doesn’t untap immediately, for example.) The creature will just untap as normal during its controller’s next untap step.
• WWizards of the Coast2008-10-01
  Official Ruling
  Ice Floe doesn’t track the creature’s controller. If the affected creature changes controllers, Ice Floe will prevent it from being untapped during its new controller’s untap step.
• WWizards of the Coast2008-10-01
  Official Ruling
  You may target a tapped creature with Ice Floe’s activated ability.
• WWizards of the Coast2008-10-01
  Official Ruling
  The targeted creature is not removed from combat. Its attack will continue as normal.

Rulings via Scryfall