Boggart Forager

A red one-drop whose entire activated ability is to make a player shuffle their library: as removal or threat it does nothing, and as a body it is a plain 1/1 until you spend the mana to throw it away. The function is anti-tutor, anti-fateseal interference, and a release valve against cards that ask a player to set up the top of their library. Scry, Brainstorm-style restacking, miracle costs that depend on the next draw, predictive ordering from a clairvoyant effect: once that setup has resolved, this can sacrifice itself before the relevant draw and scatter all of it back into the deck. The cost is the joke and the constraint at once, since the body is the resource and you only get one use, so the answer is always a single, deliberate shuffle aimed at the exact moment a top-of-library plan resolves. It reads as a cute Goblin throwaway, but the timing window is real: an instant-speed sacrifice that resolves before the opponent draws turns their carefully arranged top deck into noise. That the shuffle is stapled to a 1/1 creature rather than printed on an instant is the curiosity here. The ability lives on something that can be killed, bounced, or simply ignored before it ever activates, which is what keeps a hard answer to library manipulation from being oppressive: you have to keep the Goblin alive and on the board, waiting, until the moment it earns its sacrifice.