Choke

Mercenaries don't untap during their controllers' untap steps.

Cumulative upkeep (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)

Snow permanents don't untap during their controllers' untap steps.

Enchant tapped creature

Enchanted creature doesn't untap during its controller's untap step.

Cast this spell only if you control a snow land.

Cumulative upkeep (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)

Creatures with flying don't untap during their controllers' untap steps.

, : Target creature doesn't untap during its controller's next untap step.

At the beginning of your end step, untap all lands you control.