Summon: Fat Chocobo

What the Saga frame does here is buy a body twice. Most creature Sagas hand you value on entry and then leave a fragile permanent to sit through its chapters; this one arrives as a 4/4 and immediately spins off a 2/2 that scales off your land drops, so the tempo cost of committing a five-mana enchantment creature is partly refunded before the first attack step. The three-chapter trample grant that follows is the more interesting piece: it turns the chapter clock from a countdown-to-sacrifice into a repeatable green Overrun that fires on your draw step for three consecutive turns, right as a go-wide board is at its widest. Green typically gets trample as a single pump spell you have to draw into; wiring it to a Saga makes the payoff guaranteed and recurring, arriving on schedule rather than off the top. The Bird token's land-triggered pump keeps it relevant into the late chapters, so the whole thing reads as a self-contained aggression engine: a threat, a scaling attacker, and three turns of evasion, all on one card that eventually sacrifices itself out of the way. The design tension is entirely in the sacrifice-after-IV clause, which caps the trample loop at three swings and forces you to have already built the board it wants to push through.