The Watcher in the Water

Flash
When The Watcher enters the battlefield, create
a 1/1 blue tentacle token and tap target creature
for each {u} spent to cast it. Creatures tapped this
way don't untap during their controller's untap
step as long as you control The Watcher.
Whenever a source an opponent controls deals
damage to a squid or tentacle you control, they
may untap a creature they control.