Frozen Titan's Sleep

Whenever Frozen Titan's Rest enters the battle-
field,tap target permanent. It does not untap
during its controllers next untap phase.
Whenever you attack with all creatures you
control, tap target permanent. It does not untap
during its controllers next untap phase.
"Ice war mountain gives the power and curse of
evercold to all who summit it. One day the sleeper
awakens, e'll claim all who have stood on his head."
- Getha the crone, village blasphemer.