| Keen-Eyed CuratorBloomburrow Promos · 181s | Bloomburrow Promos | 181s | Rare | €2.11 |
| Keening StoneThe Brothers' War Retro Artifacts · 26 | The Brothers' War Retro Artifacts | 26 | Rare | €0.25 |
| Keening StoneThe Brothers' War Retro Artifacts · 89 | The Brothers' War Retro Artifacts | 89 | Rare | €0.28 |
| Keening StoneThe Brothers' War Retro Artifacts · 89z | The Brothers' War Retro Artifacts | 89z | Rare | €140.86 |
| Keening StoneCommander 2016 · 259 | Commander 2016 | 259 | Rare | €0.36 |
| Keening StoneRise of the Eldrazi · 219 | Rise of the Eldrazi | 219 | Rare | €0.19 |
| Keeper of KeysConspiracy: Take the Crown · 34 | Conspiracy: Take the Crown | 34 | Rare | €1.91 |
| Keeper of KeysTreasure Chest · 15 | Treasure Chest | 15 | Rare | — |
| Keeper of KeysThe List Tokens · CN2-34 | The List Tokens | CN2-34 | Rare | — |
| Keeper of ProgenitusShards of Alara · 135 | Shards of Alara | 135 | Rare | €0.52 |
| Keeper of SecretsWarhammer 40,000 Commander · 78 | Warhammer 40,000 Commander | 78 | Rare | $7.44 |
| Keeper of SecretsWarhammer 40,000 Commander · 78★ | Warhammer 40,000 Commander | 78★ | Rare | $16.70 |
| Keeper of the AccordCommander Legends · 27 | Commander Legends | 27 | Rare | €0.57 |
| Keeper of the AccordCommander Legends · 621 | Commander Legends | 621 | Rare | €2.33 |
| Keeper of the AccordMurders at Karlov Manor Commander · 70 | Murders at Karlov Manor Commander | 70 | Rare | $0.55 |
| Keeper of the AccordMarch of the Machine Commander · 191 | March of the Machine Commander | 191 | Rare | €0.55 |
| Keeper of the AccordCommander Legends Promos · 27p | Commander Legends Promos | 27p | Rare | €0.73 |
| Keeper of the AccordFallout · 164 | Fallout | 164 | Rare | $0.48 |
| Keeper of the AccordFallout · 451 | Fallout | 451 | Rare | €0.61 |
| Keeper of the AccordFallout · 692 | Fallout | 692 | Rare | €1.84 |
| Keeper of the AccordThe List Tokens · CMR-27 | The List Tokens | CMR-27 | Rare | €0.62 |
| Keeper of the AccordFallout · 979 | Fallout | 979 | Rare | €2.24 |
| Keeper of the AccordMagic Online Promos · 86016 | Magic Online Promos | 86016 | Rare | — |
| Keeper of the Crown // Coronation of the WildsMystery Booster 2 Tokens · 577 | Mystery Booster 2 Tokens | 577 | Rare | €0.10 |
| Keeper of the Nine GalesLegions · 42 | Legions | 42 | Rare | €3.08 |
| Keeper of the Nine GalesThe List Tokens · LGN-42 | The List Tokens | LGN-42 | Rare | €7.83 |
| Keeper of TresserhornAlliances · 52 | Alliances | 52 | Rare | $0.60 |
| Kefka, Dancing MadFinal Fantasy Commander · 84 | Final Fantasy Commander | 84 | Rare | $0.39 |
| Kefka, Dancing MadFinal Fantasy Commander · 174 | Final Fantasy Commander | 174 | Rare | $1.47 |
| Kefnet's Last WordHour of Devastation · 39 | Hour of Devastation | 39 | Rare | $0.22 |
| Kefnet's Last WordHour of Devastation Promos · 39s | Hour of Devastation Promos | 39s | Rare | $0.70 |
| Keiga, the Tide StarChampions of Kamigawa · 72 | Champions of Kamigawa | 72 | Rare | €1.13 |
| Keiga, the Tide StarCommander Legends: Battle for Baldur's Gate · 725 | Commander Legends: Battle for Baldur's Gate | 725 | Rare | €0.20 |
| Keiga, the Tide StarIconic Masters · 63 | Iconic Masters | 63 | Rare | €0.73 |
| Keiga, the Tide StarTarkir: Dragonstorm Commander · 156 | Tarkir: Dragonstorm Commander | 156 | Rare | €0.30 |
| Kei TakahashiLegends · 238 | Legends | 238 | Rare | €7.41 |
| Keldon BattlewagonProphecy · 139 | Prophecy | 139 | Rare | $0.25 |
| Keldon FirebombersProphecy · 94 | Prophecy | 94 | Rare | €1.19 |
| Keldon FlamesageDominaria United · 135 | Dominaria United | 135 | Rare | $0.11 |
| Keldon FlamesageDominaria United · 407 | Dominaria United | 407 | Rare | €0.14 |
| Keldon FlamesageDominaria United Promos · 135p | Dominaria United Promos | 135p | Rare | €0.25 |
| Keldon FlamesageDominaria United Promos · 135s | Dominaria United Promos | 135s | Rare | €0.22 |
| Keldon FlamesageMagic Online Promos · 103444 | Magic Online Promos | 103444 | Rare | — |
| Keldon NecropolisInvasion · 325 | Invasion | 325 | Rare | €0.71 |
| Keldon NecropolisVintage Masters · 300 | Vintage Masters | 300 | Rare | — |
| Keldon TwilightPlaneshift · 112 | Planeshift | 112 | Rare | $0.42 |
| Kellan, Daring Traveler // Journey OnThe Lost Caverns of Ixalan · 231 | The Lost Caverns of Ixalan | 231 | Rare | €0.27 |
| Kellan, Daring Traveler // Journey OnThe Lost Caverns of Ixalan · 341 | The Lost Caverns of Ixalan | 341 | Rare | €0.16 |
| Kellan, Daring Traveler // Journey OnThe Lost Caverns of Ixalan Promos · 231p | The Lost Caverns of Ixalan Promos | 231p | Rare | $0.16 |
| Kellan, Daring Traveler // Journey OnThe Lost Caverns of Ixalan Promos · 231s | The Lost Caverns of Ixalan Promos | 231s | Rare | $0.43 |