Silver Dragon

Flying, Vigilance, Age-Up: {1}{w}{u} (add an age
counter as a sorcery), Age 2+: First Strike,
Age 3+: Menace, Age 4+: Double Strike
Age (The creature enters the battlefield with 1
age counter. For each age counter, it gets +2/+1
and any benefits noted at specific ages. A creature
can't have more than 4 age counters.)
Whenever Silver Dragon has an age counter put
on it, tap target creature an opponent controls.
That creature doesn't untap during its
controller's next untap step.