Mummy Paramount

White Zombies is the wrinkle here, and the trigger leans all the way into it: a self-pump that fires whenever any other Zombie you control enters, not just on combat or on cast. That breadth sets the ceiling. Token generation and recursion feed it as readily as curving out does, and a turn that puts two or three Zombies onto the battlefield stacks the bonuses one atop the next, so a 2/2 can swing as a 4/4 or larger before anyone gets to block. What keeps it from snowballing is the duration: the bonus lasts only until end of turn, so it evaporates in the cleanup step and the creature is never bigger than the attack you commit to right now. That makes it a beater that scales to the width you generate this turn rather than a permanent threat you stockpile around. The body pumps itself and no one else, which is the honest read on what it offers: it converts a wide Zombie turn into a single oversized attacker, not a board-wide swing. White's tribal Zombie tools have always run thinner than black's, which is the context that makes a payoff like this notable at all; it asks an aggressive shell to play to the board and cash that width into damage inside one combat step.