Hyrax Tower Scout

The enters-the-battlefield untap is the whole reason to look twice at an otherwise plain 3/3. The trigger fires when the creature resolves, so the untap only pays off if the body sticks: counter the spell and there is no value, but let it land and you get a guaranteed activation with no follow-up cost. The obvious line is pseudo-vigilance: untap a creature you already tapped to attack this turn and send it back to hold the fort on defense. The sharper axis is the tap ability it feeds. Any creature with a tap-to-activate line (a mana dork, a card-draw engine, a fight effect, a ping) gets a second use the instant this enters, and blink or bounce effects turn that into a repeatable double-activation. The target is restricted to a creature, so the untap can rescue your own tapped-out attacker or free an ally's ability, but it will never touch a tapped artifact or land. The design lineage runs through the old crew of creatures built to reset a key tapped creature; the difference here is that the utility rides on a fair beater rather than a fragile enabler, so the card is a body first and a combo piece second. That pricing is why the effect reads as small until the right tap engine sits across the table: unaccompanied, it swings for three and does nothing else, but stapled to an activated ability it hands that ability a free second use every time it enters.