Jandor's Saddlebags

Untap effects on a repeatable, colorless engine are a design lever Wizards has handled carefully ever since, and this is where the lever first appeared. The activation cost is steep by modern standards (three mana plus the tap, to untap a single creature), but the shape it set down is the one every later untap artifact has either embraced or deliberately walked back from: a colorless, repeatable way to double a tap ability. The original charges full price for what it does, which is why it reads as quaint now but was a genuine combo enabler in its era: any creature with a tap ability worth using twice (mana producers, pingers, tappers that lock down a defender) became a two-card engine the moment the saddlebags arrived. As a colorless artifact with no summoning sickness to wait out, it can be fired off immediately and at instant speed, which let it untap a blocker after combat math was committed or squeeze a second activation out of a creature in response to removal. Later untappers refined the rate or bolted on riders, but the core idea traces back here. The flavor is also doing real work; tying an untap effect to a piece of riding equipment is the kind of literal-minded design Arabian Nights specialized in, and it gave the mechanic a physical metaphor (a rested mount) that later, more abstract untappers quietly inherited without ever naming.