Instantáneo
Pon un contador -1/-1 sobre la criatura objetivo, luego prolifera. (Eliges cualquier número de permanentes y/o jugadores con contadores sobre ellos y pones sobre cada uno un contador de un tipo que ya tenga.)
Players can respond to a spell or ability whose effect includes proliferating. Once that spell or ability starts to resolve, however, and its controller chooses which permanents and players will get new counters, it's too late for anyone to respond.