Your opponent switches the Defending Pokémon with 1 of his or her Benched Pokémon, if any. (Do the damage before switching the Pokémon.)
40Mega Drain
Remove a number of damage counters from Butterfree equal of half the damage done to the Defending Pokémon (after applying Weakness and Resistance) (rounded up to the nearest 10). If Butterfree has fewer damage counters that that, remove all of them.
“In battle, it flaps its wings at high speed to release highly toxic dust into the air.”
How much is Butterfree #21/110 worth?
A raw copy of Butterfree #21/110 (Legendary Collection, 2002) is worth about $9.20 right now, based on the latest market data from November 6, 2026. Across the 2 printings we track, copies run anywhere from $3.50 to $3,004.38 depending on the version you're holding.
Grading changes the math on this one: a PSA 10 is valued around $243.06, roughly 26.4x the raw price, while a PSA 9 sits near $47.07. 850 copies have been graded to date, and 4% of them came back a 10 — worth knowing before you pay grading fees.
We update this valuation every night from live market data and verify it against real completed sales — see the chart above for how Butterfree has moved over time.