Gem-Merchant

Level 3 EARTH/Spellcaster Effect
1000 ATK / 1000 DEF

During the Damage Step, in either player's turn, when a face-up EARTH Normal Monster you control attacks or is attacked: You can send this card from your hand to the Graveyard; that monster gains 1000 ATK and DEF until the End Phase.

Rulings – Yugipedia

Printings:

Duel Terminal 5a: DT05-EN021 (Duel Terminal Normal Parallel Rare) - 2011-05-29
Hidden Arsenal 5: Steelswarm Invasion: HA05-EN006 (Super Rare) - 2011-12-01
Battles of Legend: Monster Mayhem: BLMM-EN109 (Ultra Rare) - 2025-08-28

Prices:

Cardmarket: 0.02 €
TCGplayer: $ 0.08