Brock's Onix is card #21 of 132 in Gym Heroes (2000), a Rare illustrated by Benimaru Itoh. At about $17.21 it is the #43 most valuable card in the set. In a Gym Heroes booster it turns up about once every 35 packs. It is one of 31 Onix cards printed so far.
1999Base Set
2000Gym Heroes
2002Legendary Collection
2004Team Rocket Returns
2008Stormfront
2013Plasma Freeze
2019Hidden Fates
2022Pok茅mon GO

















See the full Gym Heroes card list
An ungraded Brock's Onix from Gym Heroes sells for about $17.21. A PSA 10 is worth more, roughly $224 by our estimate, and a PSA 9 around $68.84.
It is a Rare, and it shows up about once every 35 Gym Heroes packs.
Benimaru Itoh drew the art for this card.
Yes, as a digital simulator. Holobrook lets you open Gym Heroes booster packs in your browser with the set's real pull rates and keep what you pull in a digital binder. No real cards, nothing to buy.