Red-Eyes Darkness Dragon

Level 9 DARK/Dragon Effect
2400 ATK / 2000 DEF

Cannot be Normal Summoned/Set. Must be Special Summoned (from your hand) by Tributing 1 "Red-Eyes B. Dragon" and cannot be Special Summoned by other ways. This card gains 300 ATK for each Dragon-Type monster in your Graveyard.

Rulings – Yugipedia

Printings:

Structure Deck: Dragon's Roar: SD1-EN001 (Ultra Rare) - 2005-01-01
World Championship 2010 Card Pack: WCPP-EN009 (Rare) - 2010-08-14
World Championship 2010 Card Pack: WCPP-EN009 (Reprint) - 2010-08-14
Legendary Collection 4: Joey's World Mega Pack: LCJW-EN039 (Common) - 2013-10-11
Legendary Duelists: Season 1: LDS1-EN003 (Common) - 2020-07-02
Speed Duel GX: Duelists of Shadows: SGX3-ENB01 (Common) - 2023-03-30
Speed Duel GX: Duelists of Shadows: SGX3-ENB01 (Secret Rare) - 2023-03-30

Prices:

Cardmarket: 0.28 €
TCGplayer: $ 0.42