Merimar Flame Tank

Prototype (You may cast this spell with different
mana cost, color, and size. It keeps its abilities and
types.) {3}{r}{r} (5/5)
Crew 5
When Merimar Flame Tank attacks, you may
discard a card. If you do, Merimar Flame Tank
deals Damage equal to the discarded card's mana
cost to target creature or planeswalker.