USS Dace

Submerge (This creature can't be blocked except by
creatures with submerge.)

{r}{r}, {t}: USS Dace deals 3 damage to target
creature. You may pay {x}. If you do, USS Dace
deals an additional X damage to that creature.
Spend only red mana to pay X.

My three favorite things are torpedoes, torpedo
launchers, and uh, more torpedoes!