A target opponent may have you draw a card, but if they don't, you may put a creature card with equal or lesser toughness from your hand directly onto the battlefield, cheating its mana cost entirely
It managed to Top 8 GP Melbourne in March, in the hands of Jason Chung, as a rogue brew designed to fight against the Eldrazi menace (the Top 8 of GP Melbourne was incredibly weird, featuring Zombie Infestation Dredge, three copies of Eldrazi, and three copies of Living End to go with one Chord of Calling deck)
Borderless Number #13 Artist Luisa J
If a permanent enters the battlefield tapped, Teferi, Who Slows The Sunset allows you to +1 to untap it for immediate use, while also tapping pesky blockers or denying your opponent their resources
Last time, it was about 1 in 3800 packs and now its more like every 238 packs