Depth Charge Colossus is a common Artifact Creature — Dreadnought card from The Brothers' War (BRO), collector number 78. Current market price: $0.19 (foil $0.19), TCGplayer market prices via Scryfall.
Prototype {4}{U}{U} — 6/6 (You may cast this spell with different mana cost, color, and size. It keeps its abilities and types.) This creature doesn't untap during your untap step. {3}: Untap this creature.