Pokémon
Caterpie x1
Metapod x1
Butterfree x1
Koffing x1
Koffing x1
Weezing x2
Jigglypuff x2
Wigglytuff ex x2
Trainers
Potion x2
Poké Ball x2
Red Card x1
Professor's Research x2
Sabrina x1
Blue x1
Strategy
Use Caterpie if opponent is supposed to use Druddigon in the first hand, else start with Koffing (Myth Island) or Jigglypuff.
Then start charging Wigglytuff.
The strategy is to use Weezing to poison the opponent's Pokémon, continuing to attack until it is knocked out. At that point, we will bring out our Wigglytuff to finish the job with the poison/sleep combination.
Butterfree is used solely to replace potions and provide greater long-term support to Wigglytuff's HP, as we aim to stall as much as possible.
I'm experimenting a bit with the deck, and we can replace the Red Card/Blu or even the Butterfree evo line to include cards like Koga or Leaf to bring out our Weezing.
I found this deck to be very strong against ex decks without evolution lines (Legendary Birds/Celebi and Mewtwo), but it struggles slightly against decks that don’t rely on them. Even so, Wigglytuff handles these situations quite well.