Trickle's Lore: Each time a Dark or (W) Pokemon attacks, you may use this power. Discard 1 (W) Energy in your hand or attached to one of your Pokemon. That attack deals 20 more damage to the defending Pokemon, even if it wouldn't do damage otherwise. You may only use 1 "Trickle" Pokemon Power per attack.
Probably would have been very powerful at the time, since 50 for [W][W] and a discard is nothing to sneeze at, and it makes blastoise all that more powerful. It also would have been amazing to Feraligatr decks.
Also, I feel I should mention that Feebas would just be Base Set Magikarp with a different name, more or less.
As a last note, I know Trickle is a TCG attack name too, but...eh, already made, saved, and uploaded this. Too lazy, and I can;t think of anything else anyways.