Goblin Snowman

A snowman that fights forever and never dies, encoded entirely in the combat-damage prevention shield. The first ability turns every block into a no-trade exchange: it stops in front of an attacker, prevents all damage to and from itself, and walks away whole to do it again next turn. That makes the second ability the actual engine. While it sits in a blocking assignment, it can tap to ping the creature it's blocking for one, and because it isn't taking damage in return, it can hold the line indefinitely against creatures a 1/1 would normally never survive contact with. The leash is what keeps this from running away: the ping only targets a creature it's currently blocking, so the snowman cannot reach across the table to chip an untapped threat. It has to be in combat to do work, and it can only block one creature per turn, which caps its output to one creature contained per combat plus one point of damage. The flavor is doing real work too: a snowman that simply refuses to melt under attack and chips away at whatever charges it, a fixture of Ice Age's wintry texture rather than a card chasing a rate. It is a defensive wall dressed as a 1/1, and the whole package lives or dies on understanding that the prevention clause is what lets the ping ability matter at all.