Vodalian War Machine is a rare Creature — Wall card from Fallen Empires (FEM), collector number 32. Current market price: $0.58, TCGplayer market prices via Scryfall.
Defender (This creature can't attack.) Tap an untapped Merfolk you control: This creature can attack this turn as though it didn't have defender. Tap an untapped Merfolk you control: This creature gets +2/+1 until end of turn. When this creature dies, destroy all Merfolk tapped this turn to pay for its abilities.