| Karma of the Destruction SwordsmanBreakers of Shadow · 060 | Breakers of Shadow | 060 | Common | €0.14 |
| KashaAncient Prophecy · 098 | Ancient Prophecy | 098 | Secret Rare | €0.08 |
| Kashtira AkstraCyberstorm Access · 055 | Cyberstorm Access | 055 | Common | €0.06 |
| Kashtira Arise-HeartPhoton Hypernova · 046 | Photon Hypernova | 046 | Secret Rare | $12.05 |
| Kashtira Big BangPhoton Hypernova · 075 | Photon Hypernova | 075 | Common | €0.05 |
| Kashtira BirthDarkwing Blast · 060 | Darkwing Blast | 060 | Super Rare | €0.36 |
| Kashtira FenrirDarkwing Blast · 012 | Darkwing Blast | 012 | Ultra Rare | $0.58 |
| Kashtira OgreDarkwing Blast · 014 | Darkwing Blast | 014 | Common | €0.15 |
| Kashtira OverlapPhoton Hypernova · 057 | Photon Hypernova | 057 | Common | €0.06 |
| Kashtira PreparationsDarkwing Blast · 076 | Darkwing Blast | 076 | Common | €0.11 |
| Kashtira RiseheartPhoton Hypernova · 006 | Photon Hypernova | 006 | Ultra Rare | $6.10 |
| Kashtira Shangri-IraDarkwing Blast · 045 | Darkwing Blast | 045 | Super Rare | $0.41 |
| KashtiratheosisPhoton Hypernova · 058 | Photon Hypernova | 058 | Secret Rare | €2.74 |
| Kashtira UnicornDarkwing Blast · 013 | Darkwing Blast | 013 | Ultra Rare | $0.19 |
| KattapillarUnlisted Printings | Unlisted Printings | — | — | €1.88 |
| Kayenn, the Master Magma BlacksmithDuel Terminal 5a · 027 | Duel Terminal 5a | 027 | Duel Terminal Normal Parallel Rare | €0.07 |
| KazejinMetal Raiders · 026 | Metal Raiders | 026 | Super Rare | €0.08 |
| Keaf, Murk of the GhotiPhantom Nightmare · 015 | Phantom Nightmare | 015 | Super Rare | €0.25 |
| Keel, Shipwright Fur HireBurst Protocol · 050 | Burst Protocol | 050 | Common | €0.04 |
| Keeper of Dragon Magic2018 Mega-Tins · 004 | 2018 Mega-Tins | 004 | Ultra Rare | €0.07 |
| Keeper of the ShrineClash of Rebellions · 024 | Clash of Rebellions | 024 | Common | €0.08 |
| KelbekDark Crisis · 078 | Dark Crisis | 078 | Common | €0.09 |
| Kelbek the Ancient VanguardMagnificent Mavens · 027 | Magnificent Mavens | 027 | Ultra Rare | $0.29 |
| KeldoDark Crisis · 077 | Dark Crisis | 077 | Common | €0.07 |
| Keldo the Sacred ProtectorMagnificent Mavens · 025 | Magnificent Mavens | 025 | Ultra Rare | €0.46 |
| Ken the Warrior DragonAge of Overlord · 081 | Age of Overlord | 081 | Common | €0.09 |
| Kerolia the FrolicsomeBeyond the Brave · 085 | Beyond the Brave | 085 | Common | €0.07 |
| Kerzebs, the Gaoled GluttonDoom of Dimensions · 048 | Doom of Dimensions | 048 | Common | €0.06 |
| Ketu DracotailJustice Hunters · 008 | Justice Hunters | 008 | Super Rare | €0.02 |
| Keurse, the Ogdoadic LightAncient Guardians · 005 | Ancient Guardians | 005 | Super Rare | $0.30 |
| Kewl Tune B2BBlazing Dominion · 042 | Blazing Dominion | 042 | Super Rare | €0.26 |
| Kewl Tune ClipPhantom Revenge · 032 | Phantom Revenge | 032 | Super Rare | €0.11 |
| Kewl Tune CrackleBlazing Dominion · 041 | Blazing Dominion | 041 | Ultra Rare | €0.21 |
| Kewl Tune CuePhantom Revenge · 034 | Phantom Revenge | 034 | Ultra Rare | $2.28 |
| Kewl Tune Loudness WarPhantom Revenge · 038 | Phantom Revenge | 038 | Super Rare | €0.10 |
| Kewl Tune MixPhantom Revenge · 031 | Phantom Revenge | 031 | Ultra Rare | $1.88 |
| Kewl Tune PlaylistPhantom Revenge · 041 | Phantom Revenge | 041 | Rare | €0.12 |
| Kewl Tune RecoPhantom Revenge · 033 | Phantom Revenge | 033 | Ultra Rare | €2.50 |
| Kewl Tune RemixPhantom Revenge · 036 | Phantom Revenge | 036 | Super Rare | €0.16 |
| Kewl Tune RotaryBlazing Dominion · 021 | Blazing Dominion | 021 | Ultra Rare | €1.67 |
| Kewl Tune RSPhantom Revenge · 037 | Phantom Revenge | 037 | Ultra Rare | $0.68 |
| Kewl Tune SynchroPhantom Revenge · 039 | Phantom Revenge | 039 | Ultra Rare | $3.42 |
| Kewl Tune Track MakerPhantom Revenge · 035 | Phantom Revenge | 035 | Super Rare | €0.16 |
| Key MaceWorld Championship 2010 Card Pack · 002 | World Championship 2010 Card Pack | 002 | Rare | $0.72 |
| Key Mace #2World Championship 2010 Card Pack · 005 | World Championship 2010 Card Pack | 005 | Rare | $35.99 |
| Key Man the Key WarriorStarter Deck: Dawn of the Xyz · 009 | Starter Deck: Dawn of the Xyz | 009 | Common | €0.08 |
| Key MouseThe Shining Darkness · 036 | The Shining Darkness | 036 | Common | €0.27 |
| Khaos Starsource DragonRage of the Abyss · 034 | Rage of the Abyss | 034 | Common | €0.13 |
| KickfireCosmo Blazer · 089 | Cosmo Blazer | 089 | Secret Rare | $1.79 |
| Kid GuardDuelist Pack: Jaden Yuki 2 · 030 | Duelist Pack: Jaden Yuki 2 | 030 | Super Rare | $0.25 |