Timber Wolves – Alpha rare. Rare? Yeah, it has banding. Oh. Can you explain banding without looking at Gatherer? Probably not, but then I'm guessing you can't explain a 4-Out 1-In Motion Offense either ....
North Star – Legends rare. You might have forgotten about this mana-filtering artifact, since it was released in 1994. Or was it 1993? With North Star you can cast that Progenitus, Coalition Victory, or Sliver Queen with mana of any color. Just remember you'll have to pay that extra four colorless to activate it.
Lovisa Coldeyes – Coldsnap rare. Legendary leader of the Balduvian tribes, Lovisa Coldeyes has it out for the "ice wizards," sports a rare Baulduvian-blonde mop of hair, drinks from a punch-bowl-sized goblet, and could cut through any pack of rivals with that axe of hers.
Splinter Twin – Rise of the Eldrazi rare. Splinter Twin features a single human female that creates, and I quote the art description here, "her wild-eyed double." With Doubling Season in play, you'd triple her.
Lake of the Dead – Alliances rare. Turn three, tap a Swamp, play Lake of the Dead, sacrifice the tapped swamp, tap your second Swamp, activate Lake of the Dead, sacrifice your second tapped Swamp, then tap Lake of the Dead to add 4 more black mana to your mana pool for a total of 6. Is it good math? I don't know, because next turn you’ll have 4 black mana at best, if you draw, play, and sacrifice another Swamp. Just hope no one Annex this land from you after all that.
Tooth and Nail – Mirrodin rare. They say you should never play an extremely expensive spell unless it's going to win you the game. That's usually what Tooth and Nail does, so even though it's a seven-mana sorcery, it has a long and distinguished history of dominating tournament play.
Lifeline – Urza's Saga rare. Some cards just cry out to be used in abusive combos. Other cards require more work. And then there's Lifeline, which is so combo-ready, it's actually more of a challenge to come up with a way to use it that isn't broken in some weird way!
Zodiac Snake – Portal Three Kingdoms common. The Zodiac creatures of Portal Three Kingdoms represent a very unusual cycle: seven commons, four uncommons, one rare. Three black, three red, six green. All but one of them has some form of landwalk. But here's something neat: their twelve flavor texts tell the story of the set! That is, if you know the right order.
Monk Realist – Urza's Saga common. At two mana, the Monk Realist destroys enchantments. But sometimes, the uncommon three-mana Monk Idealist comes along and brings the enchantment back out of the graveyard. The lesson? These monks should get together and decide on a plan ahead of time.
Reknit – Shadowmoor uncommon. In what appears to be a rare case of an accidental hidden message in a Magic card's name, Shadowmoor's "Reknit" is "Tinker" spelled backwards—a fact that has, well, nothing whatsoever to do with the infamous card Tinker.
Reflecting Pool – Shadowmoor rare. Originally printed in Tempest, Reflecting Pool reappeared in Shadowmoor with the Lorwyn Vivid lands and Shadowmoor hybrid lands to play with. The pool shown on the Shadowmoor version reflects a vision of a very different place indeed: the sunny plane of Lorwyn, idyllic counterpart to the creepy twilit world of Shadowmoor.
Relentless Rats – Magic 2011 uncommon. On Twitter recently, director of Magic R&D Aaron Forsythe (@mtgaaron) posed the question: "How many Relentless Rats are in a playset?" Answers ranged, rather unhelpfully, from 0 to infinity, but our favorite answer came from @MikeXIV: "There are 2 playsets of relentless rats on the planet - every paper copy and every MTGO copy."
Reverberate – Magic 2011 rare. Based on the flavor of Fork, red has had the ability to copy spells from the very beginning. Saviors of Kamigawa's Twincast moved the cleanest version of that ability to blue, but with Magic 2011 and Reverberate, red takes it back—this time, without that goofy "the copy is red" text from Fork. The cosmic ballet goes on ....