Background cameos let illustrators wink at the wider Pokédex. Steelix earns 1 of those moments across 2010, distributed among various illustrators and other contributors.
Of the 1 card, HeartGold & SoulSilver contributes the largest cluster. The illustrator most often responsible is the lead illustrator, whose Steelix cameos appear in 0 of these cards.
Steelix appears as a background cameo across 1 Pokémon card.
These appearances range from clear sightings to barely-visible silhouettes, scattered across 2010 of the TCG.
Each cameo rewards collectors who pause to look closely at the card art.