Sewer Crocodile

A 4/6 for six mana is a body built to trade up and clog the ground, not to swing a race, which is the tell for what this card actually wants to do: sit in a self-mill or graveyard-value shell and turn its own filled bin into a payoff. The evasion ability costs at face, a steep tax for a single unblocked attack, but the discount rewrites the math once five or more mana values pile up in your graveyard: it drops to a single blue, and the fat blocker becomes a repeatable, cheap-to-unblock clock. That conditional cost reduction is the whole design argument. Counting mana values rather than raw card count pushes the deckbuilder toward a graveyard seeded with a spread of costs instead of a pile of one-drops, rewarding variety over volume. Left in a vacuum the crocodile is an overcosted wall; give it a well-stocked yard and it converts a defensive stat line into inevitability, on a frame big enough to survive most combat math. It is a payoff disguised as a fatty: inert until the surrounding engine switches it on, then reliably unblockable for one mana every turn thereafter.