Mega Meganium first of all, i love your card of the day!! great job, ness.. I read your Meganium report and you inspired me to make a deck based around it!! i took the idea you said of cleffa + lass, but it just loses, sometimes, especially to Magmar. help!!
4x Chikorita (50 HP)
1x Bayleef
3x Meganium (WG)
2x Pinsir
2x Rocket's Scyther
3x Cleffa
---Trainers--- (29)
4x Lass
3x Pokémon Breeder
3x Professor Oak
3x Computer Search
3x Miracle Berry
2x EcoGym
3x Bill
2x Mary
2x Item Finder
2x Pokémon Trader
1x Nightly Garbage Run
1x Gust of Wind
---Energy--- (16)
14x Grass
2x Double Colorless Energy
Strategy
Looks like you can open with a first turn lass, then Eeeeeeek, or you can just get a turn two Meganium attacking, too. You got the cards for it, but we can make a few changes in every area.
Pokémon
4 Chikorita. 3 Cleffa. Those are weak basics. You're leaving yourself with a high chance of getting either as your only basic, which can mean a quick loss for you. Back up your Pokémon a little more by adding 2 Chansey. Go with one of each Scyther. No Jungle Scyther.. well, you got resistance to fighting from the Rocket's Scyther, and fighting is almost dead now, and Cleffa has no retreat.. so why not? I like it. 62 cards.
Trainers
Drop a Bill. 2 Bill and 2 of his wife, Mary, is fine. You're playing the wrong Berry! Drop all three Miracle Berries for 3 Gold Berries. Drop one Lass, 3 is enough, so you can have One Switch to get energyless, damaged, or status effected Pokémon on the bench. One Switch can make a big difference in a deck. EcoGym won't save your colorless, and won't stop them from slowing you down. Try to mess them up with No Removal Gym instead. 60 cards.
Energy
You don't need that much grass, so why don't you drop 4, so you can play 2 Full Heal Energy and max out on double colorless?
Here's the fixed deck...
---Pokémon--- (17)
4x Chikorita (50 HP)
1x Bayleef
3x Meganium (WG)
2x Pinsir
2x Rocket's Scyther
3x Cleffa
2x Chansey
---Trainers--- (27)
3x Lass
3x Pokémon Breeder
3x Professor Oak
3x Computer Search
3x Gold Berry
2x No Removal Gym
2x Bill
2x Mary
2x Item Finder
2x Pokémon Trader
1x Nightly Garbage Run
1x Gust of Wind
---Energy--- (16)
10x Grass
4x Double Colorless Energy
2x Full Heal Energy
Good luck with the deck. Ness.