Great Whale
Seven mana out, seven lands back: the trigger refunds the card's full cost the instant it resolves, and that arithmetic is the only reason anyone ever cast it. The 5/5 body is a vehicle, not a threat. This was one of the original free-spell engines from the era of the most broken Standard the game has produced, sharing a skeleton with the land-untapping tricks that defined those summers. The key restriction is that the trigger untaps lands, not permanents at large, so the way to break even is to untap lands that produce more than a single mana each: a bounce land, Nykthos, a Forest carrying Wild Growth. Once your seven untapped lands yield more than the seven needed to recast it, the Whale stops being a creature and becomes plumbing for mana, storm count, or recursion fuel. It is the cruder relative of Palinchron, which untaps the same number but bundles in a self-bounce clause that closes the loop on its own; the Whale needs an outside blink or recursion effect to complete the cycle. Designers have spent the years since trying to keep land-untap effects contained, because a body that refunds its own casting cost tends to graduate to a banned list. The Whale endures as a comparatively honest take on the trick: still abusable, but it demands real external work to break, the signature of an age when that work sat one card away.
