If I have a Double Colorless Energy attached to Tangrowth, will its "Grind" attack do an extra 20 or 40 damage for that energy card?
It will do an extra 40 damage. Grind looks at the total amount of energy attached, not energy cards.
Grind






x2
-20
GrindDoes 20 damage times the amount of Energy attached to Tangrowth.


Plow OverFlip a coin. If heads, the Defending Pokémon is now Paralyzed. If tails, put 1 Energy card attached to the Defending Pokémon in the Lost Zone.
If I have a Double Colorless Energy attached to Tangrowth, will its "Grind" attack do an extra 20 or 40 damage for that energy card?
It will do an extra 40 damage. Grind looks at the total amount of energy attached, not energy cards.