Teeterpeak Ambusher

Three toughness is the whole design conceit here. Most firebreathers are glass beaters that fold to a chump block or an incidental ping, so the pump ability reads as pure offense with a fragile frame underneath. This one flips that math: the defensive body means it survives the attacks it makes, blocking early and then converting surplus red mana into reach later without dying to the trade. It costs nothing meaningful on the early curve and demands everything from a late-game glut of lands, where for +2/+0 scales as far as your untapped mana allows. That puts it in the long tradition of pump-per-mana bodies that turn mana flood into damage, from the humble Firebreathing aura onward, but the survivable back gives it a role most of those creatures never had: a blocker that becomes the win condition once the game stalls. Nothing about the plan is subtle, and it does not need to be. Hold the line while the board fills, then point it at the opponent and pour every available land's worth of mana into the pump until the toughness that kept it alive stops mattering.