Plated Seastrider

A 1/4 for two blue mana is a wall by stat-line, but the toughness is the point of the design rather than an apology for the power. Defensive blue creatures live or die on how well they brick early aggression, and four toughness sits above the damage most one- and two-drops can put on the board, which buys a control or tempo deck the turns it needs to set up. The single power is the honest cost: this thing does not threaten to win, it threatens to stop you from winning, and the mono-blue cost keeps it locked to decks that already want to durdle behind a curve. As a piece of the early-game wall lineage it is plain work, a body whose only job is to absorb a hit and stay home, but it does that job cleanly and without conditions. There is no upside ability waiting to flip the card into a threat, no metalcraft trigger, no evasion bolted on; what you see is the entire contract. That makes it a fixture of the unglamorous part of deckbuilding: the slot you fill when you have decided the game plan is to survive and you need toughness per mana more than you need anything clever.