Slithery Stalker

Color-hosing dressed up as a creature, and built so the hate only lands where it stings. The exile clause names green or white specifically: an answer aimed at two colors that traditionally lean on big or hard-to-kill bodies, with a removal effect that sidesteps black's old trouble against indestructible or regenerating threats. But the design refuses to let the answer be permanent. The exiled creature comes back the instant the Stalker dies or otherwise leaves, which means the 1/1 frame is doing real work: it is a fragile vessel holding a hostage, and any removal the opponent points at it returns their creature for free. The swampwalk turns that vessel into a clock, but only against a Swamp-controlling opponent: against a deck splashing or anchored in black, the body that was too small to attack profitably becomes unblockable and can pressure the hostage's owner directly. The whole package reads as an early-era statement about black's revenge against green and white: an answer you have to defend rather than fire and forget, where holding the creature hostage is a temporary lease, not a sale. Strip away the swampwalk flavor and the effect anticipates a pattern Wizards would return to repeatedly: the temporary exiler whose own death undoes its work, forcing the controller to weigh how long they can keep the lid on.