Kjeldoran Frostbeast

Block with this 2/4 and the math inverts: the creature it stops dies at end of combat, regardless of how much damage it dealt or took. That end-of-combat timing is the entire engineering problem. Because the destruction fires after damage rather than alongside it, the Frostbeast has to survive the combat to collect; throw it in front of something that deals four or more and it dies during the damage step, the trigger never resolves, and the attacker walks away clean. The toughness of 4 is the lever, not a footnote: it lets the Frostbeast outlast most of what early green and white could land in a single block, so it lives long enough to clear whatever it tangled with. An active regeneration shield will still replace the destruction and save the blocked creature, since regeneration replaces destruction whenever it happens. The effect is a deathtouch trigger printed years before deathtouch existed as a keyword, gated twice over: once behind a body sturdy enough to keep doing it, and once behind the requirement that the body win the combat before the destruction ever fires. It reads as a defensive wall and functions as a trap, and the difference between the two is whether the attacking player bothers to read the trigger before sending creatures into it.