Trample
Abominable Treefolk's power and toughness are each equal to the number of snow permanents you control.
When Abominable Treefolk enters the battlefield, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.
Abominable Treefolk's last ability can target a creature that's already tapped. That creature won't untap during its controller's next untap step.
As long as Abominable Treefolk is on the battlefield, its first ability will count itself, so it'll be at least 1/1.
The ability that defines Abominable Treefolk's power and toughness works in all zones, not just the battlefield.