Ka-Zar of the Savage Land

Two engines wired to feed each other. The library-peeking package is familiar green work: constant visibility on your next card plus the ability to play lands directly off the top of your deck, which turns your draw step into extra selection and stretches your land count without spending cards from hand. On its own that is a value effect, not a threat. The enters trigger is what supplies the clock, handing you Zabu, a 2/2 Cat that grows a counter every time a land you control enters. The two abilities are deliberately linked: a land played off the top isn't only card advantage, it's a landfall trigger, so the same engine that keeps resources flowing is also stacking counters on the Cat. A 3/2 body for five mana does little on its own, and the card doesn't pretend otherwise; the legendary Barbarian here is a delivery mechanism, and the growth all lives on the token. The genuinely useful wrinkle is that Zabu carries its own name and its own landfall clause, so it survives Ka-Zar dying or bouncing and keeps scaling on any landfall trigger you generate afterward, whether the land came off your deck or straight from hand. Note the ceiling, too: you still play only one land per turn under normal rules, and the top card is a land only when it happens to be one, so the engine smooths draws rather than guaranteeing them.