Mischievous Poltergeist

A small evasive body with a self-funding insurance policy: the regeneration shield costs nothing but life, paid as many times as your life total allows. That design choice is the whole personality of the card. Regeneration historically came gated behind mana, which means a removal-heavy opponent can simply trade with you on tempo by forcing you to hold up the shield. Pricing the effect in life instead decouples the survival ability from your mana, so the Spirit can keep flapping in for a point and keep regenerating against sweepers and combat-based blockers without ever tapping out for the privilege. The friction is built into the resource itself: life is a finite, attacker-shrinking pool, and a 1/1 trading repeatedly off its own life total is a slow clock at best. What you get is a stubborn, hard-to-kill chump and chip-damage threat that resists damage-based removal and any combat that does not exile or bounce; what you give up is the speed the body never had. It is a clean expression of black's recurring bargain, paying life for permanence, in the smallest possible package.