Edit: Finally, a scan of the card! This is the League promo version of Claydol.
Name: Claydol
Type: Fighting
Stage 1 (Evolves from Baltoy)
HP: 80
Poke-Power: Cosmic Power
Once during your turn (before your attack), you may choose up to 2 cards from your hand and put them on the bottom of your deck in any order. If you do, draw cards until you have 6 cards in your hand. This power can't be used if Claydol is affected by a Special Condition.
(FC) Spinning Attack 40
Weakness: (G) +20
Resistance: None
Retreat: (CC)
Analysis
HP: 80 is okay for a Stage 1. Several cards can OHKO Claydol on the bench, like Garchomp C lv. X and Raikou & Entei Legend.
Weakness: Jumpluff (HGSS) is the only card in tournament play that hits Claydol for Weakness. Otherwise, Weakness is not a factor.
Resistance: Claydol has none, so let's move on.
Retreat: Two is pretty steep for a Stage 1. Use Switch or Warp Point, or if you absolutely have to, use a Double Colorless Energy.
Cosmic Power: The sole reason that Claydol is in almost every tournament caliber deck. This power basically lets you return two cards that you have no use for at the moment in order to draw up to 6 more cards. This is especially useful when your hand has been reduced to only one or two cards, since you can get a fresh hand of 6 after one Cosmic Power. Due to this, many players will make it a priority to take out any Claydol you send out in order to stop you from drawing constantly.
Spinning Attack: 40 for two Energy is pretty good, but why risk your draw power when there are much better attackers out there?
Combos
Night Teleporter: This Trainer from Supreme Victors lets you flip a coin and if you get heads, you shuffle your hand into your deck and then grab any card from your deck. Then you use Cosmic Power to return that card to your deck and draw six. This is only really useful if you have eight or more cards in your hand, since Cosmic Power wouldn't get you any cards otherwise.
Ratings
Modified (current): The only decks that I know of that don't use Claydol are SP decks, since they have their own support cards. The fact that Claydol is easily sniped, its hefty Retreat Cost, and mediocre attack is enough reason for Claydol to only get a 9 instead of a 10. Otherwise, Claydol should be in every Modified deck until September just for the Cosmic Power! (9/10)
Conclusion
Claydol has been around since 2008 and has definitely made the game much faster than in previous years. With its departure in September, decks that rely on set up will be a lot slower than the faster SP decks until SP's themselves get rotated or a suitable replacement for Claydol is found. Yeah, Claydol is THAT important!