Brock's Sandslash is card #36 of 132 in Gym Challenge (2000), a Uncommon illustrated by Atsuko Nishida. At about $8.22 it is the #70 most valuable card in the set. In a Gym Challenge booster it turns up about once every 14 packs. It is one of 25 Sandslash cards printed so far.
1999Fossil
2000Gym Heroes
2003Skyridge
2005Delta Species
2010HeartGold & SoulSilver
2015BREAKthrough
2019Unbroken Bonds
2023151

















See the full Gym Challenge card list
An ungraded Brock's Sandslash from Gym Challenge sells for about $8.22. A PSA 10 is worth more, roughly $107 by our estimate, and a PSA 9 around $32.88.
It is a Uncommon, and it shows up about once every 14 Gym Challenge packs.
Atsuko Nishida drew the art for this card.
Yes, as a digital simulator. Holobrook lets you open Gym Challenge 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.