| Lara Croft, Tomb Raider (2 variants) | 1501 |
| Laboratory Maniac (2 variants) | 1097 |
| Laboratory Maniac | 1394★ |
| Laboratory Maniac | 1394 |
| Kynaios and Tiro of Meletis (2 variants) | 2806 |
| Kumena, Tyrant of Orazca | 1412★ |
| Kumena, Tyrant of Orazca | 1412 |
| Kruphix, God of Horizons | 73 |
| Kroxa, Titan of Death's Hunger (2 variants) | 225 |
| Krosan Grip (2 variants) | 481 |
| Krosan Beast | 196 |
| Krenko, Tin Street Kingpin (2 variants) | 1027 |
| Krenko, Mob Boss | 2407 |
| Kratos, Stoic Father (2 variants) | 2213 |
| Kratos, God of War (2 variants) | 2207 |
| Krark's Thumb // Krark's Thumb | 383 |
| Krark, the Thumbless // Krark, the Thumbless (2 variants) | 1543 |
| Kozilek, the Great Distortion (2 variants) | 493 |
| Kothophed, Soul Hoarder (2 variants) | 162 |
| Kothophed, Soul Hoarder | 162★ |
| Koth of the Hammer (2 variants) | 1248 |
| Korvold, Fae-Cursed King (2 variants) | 1625 |
| Koma, Cosmos Serpent (2 variants) | 1765 |
| Kokusho, the Evening Star | 1528 |
| Kogla, the Titan Ape | 1274 |
| Kodama's Reach (2 variants) | 2294 |
| Kodama's Reach (2 variants) | 371 |
| Knuckles the Echidna (2 variants) | 2082 |
| Knight of the White Orchid (2 variants) | 1045 |
| Knight of the White Orchid | 7139 |
| Knight Exemplar (2 variants) | 1044 |
| Knight Exemplar (2 variants) | 707 |
| Klauth, Unrivaled Ancient (2 variants) | 2499 |
| Kira, Great Glass-Spinner (2 variants) | 421 |
| Kiora, Behemoth Beckoner | 532 |
| Kiora, Behemoth Beckoner (2 variants) | 1700 |
| Kindred Summons | 1901 |
| Kiki-Jiki, Mirror Breaker (2 variants) | 1659 |
| Kezzerdrix (2 variants) | 826 |
| Kessig Wolf Run (2 variants) | 355 |
| Kess, Dissident Mage (2 variants) | 1167 |
| Keranos, God of Storms | 79 |
| Ken, Burning Brawler (2 variants) | 430 |
| Kelsien, the Plague (2 variants) | 1558 |
| Keen Duelist (2 variants) | 828 |
| Kediss, Emberclaw Familiar (2 variants) | 2364 |
| Kaya, Ghost Assassin (2 variants) | 247 |
| Kaya, Bane of the Dead | 531 |
| Kasmina, Enigmatic Mentor | 507 |
| Karrthus, Tyrant of Jund (2 variants) | 1250 |