Jade Avenger

A green two-drop that is worth exactly what it looks like until the block is declared, and then worth two power more. Bushido only fires inside combat: block or get blocked, and once assignment locks in, the 2/2 swells to a 4/4 while the boost is already baked into the exchange. The opponent can count the number ahead of time and still has to eat it, because the growth arrives after they have committed to the trade. Running a two-power attacker into this frog on defense resolves as a one-sided loss, and chumping it on offense turns a throwaway blocker into a wasted card just as cleanly; the ability punishes the defender's willingness to swap in either direction. What holds it in check is that the pump lives entirely in the block step. Outside of combat this creature cannot grow itself, does nothing against removal, and offers no reach in a race where no one is blocking. Bushido was the connective tissue of the samurai theme in its era, and the Frog Samurai type line points straight back to those roots, but the underlying tax is older than any samurai block: green has long printed bodies that read as an even trade and quietly are not, converting the opponent's instinct to block into a liability.