Kraul Swarm

A 4/1 flyer for five is a body that trades into almost anything and dies to a stiff breeze, and its fragility is a feature: the value lives in the graveyard, not on the battlefield. The recursion clause asks for both halves of a working engine at once, the Swarm sitting in your graveyard and a spare creature card in hand to pitch, and that dual requirement is what keeps the loop honest. Each return is gated behind mana and a creature discard together, so the card cannot fuel itself; the shell around it has to keep drawing bodies worth throwing away. That makes it the reward for an attrition build that churns through creatures, where a one-toughness flyer that keeps coming back is a steadier source of damage than its fragility suggests, turning otherwise-dead late-game creature draws into reach in the air and a chip clock that grinds out games a single removal spell cannot end. The Insect Warrior typing nods at the black-green bug-and-rot cluster, the same lineage that supplies those grindy decks their swarms and sacrifice fodder. Strip away the activated ability and this is filler nobody sleeves; the recursion is the entire reason the card exists, converting redundant bodies in hand into an evasive threat that refuses to stay dead.