Number 17: Leviathan Dragon

Level 3 WATER/Dragon Xyz Effect
2000 ATK / 0 DEF

2 Level 3 monsters
Once per turn: You can detach 1 Xyz Material from this card; this card gains 500 ATK. If this card has no Xyz Material, it cannot attack your opponent directly.

Rulings – Yugipedia

Printings:

Generation Force: GENF-EN039 (Ghost Rare) - 2011-08-16
Generation Force: GENF-EN039 (Ultimate Rare) - 2011-08-16
Generation Force: GENF-EN039 (Ultra Rare) - 2011-08-16
Collectible Tins 2011 Wave 1: CT08-EN001 (Secret Rare) - 2011-08-25
Battle Pack: Epic Dawn: BP01-EN027 (Rare) - 2012-05-24
Battle Pack: Epic Dawn: BP01-EN027 (Starfoil Rare) - 2012-05-24
Duelist League 15 participation cards: DL15-EN012 (Rare) - 2012-12-15
Star Pack 2013: SP13-EN023 (Common) - 2013-03-01
Star Pack 2013: SP13-EN023 (Starfoil Rare) - 2013-03-01
Brothers of Legend: BROL-EN000 (Starlight Rare) - 2021-12-02
Quarter Century Stampede: RA04-EN154 (Platinum Secret Rare) - 2025-04-10
Quarter Century Stampede: RA04-EN154 (Quarter Century Secret Rare) - 2025-04-10

Prices:

Cardmarket: 0.34 €
TCGplayer: $ 0.57