Slumbering Walker

It enters shrunk to a 2/5 and grows back into its printed 4/7 as it spends its own ability, and that inversion gives the card its shape. Each of your end steps you may shave one of the -1/-1 counters it came down with; when you do, a reflexive trigger returns a small creature from your graveyard to the battlefield. Two shavings, two returns, and by the time the engine has run dry the body has climbed to a genuine wall. The scheduling turns recursion into a two-step plan you can see coming: a slow bloom rather than a burst, with the returned creature sitting up as a blocker into the opponent's turn. Because the trigger fires on your own end step, the engine starts the same turn it lands, provided the graveyard holds something worth reaching for. The power-2-or-less clause keeps the targets modest, pointing at mana dorks, sacrifice fodder, and one-drop utility creatures rather than a loop of bombs, in the tradition of white's small-creature recursion (Reveillark, Sun Titan) narrowed here to the humblest bodies on the board. Note the split in the ability: removing the counter is its own choice, and the reanimation rides in behind it as a separate reflexive trigger. That means an empty graveyard never strands the growth. You can still shave to inflate the body, forfeiting only the return, so the card climbs toward 4/7 on schedule whether or not there is anything left to raise.