| Undercity Scrounger // Undercity ScroungerNeon Dynasty Art Series · 42 | Neon Dynasty Art Series | 42 | — | — |
| Undercity's EmbraceRavnica Allegiance · 89 | Ravnica Allegiance | 89 | Common | €0.04 |
| Undercity's EmbraceThe List Tokens · RNA-89 | The List Tokens | RNA-89 | Common | €0.06 |
| Undercity's EmbraceRavnica Remastered · 96 | Ravnica Remastered | 96 | Common | €0.08 |
| Undercity SewersMurders at Karlov Manor · 270 | Murders at Karlov Manor | 270 | Rare | $16.06 |
| Undercity SewersMurders at Karlov Manor · 332 | Murders at Karlov Manor | 332 | Rare | $20.38 |
| Undercity SewersMurders at Karlov Manor Promos · 270p | Murders at Karlov Manor Promos | 270p | Rare | €18.24 |
| Undercity SewersMurders at Karlov Manor Promos · 270s | Murders at Karlov Manor Promos | 270s | Rare | €22.27 |
| Undercity SewersTeenage Mutant Ninja Turtles Source Material · 20 | Teenage Mutant Ninja Turtles Source Material | 20 | Mythic Rare | $8.50 |
| Undercity ShadeRavnica: City of Guilds · 110 | Ravnica: City of Guilds | 110 | Uncommon | €0.12 |
| Undercity // The InitiativeBattle for Baldur's Gate Oversized Cards · 20 | Battle for Baldur's Gate Oversized Cards | 20 | — | €6.54 |
| Undercity // The InitiativeCommander Legends: Battle for Baldur's Gate Tokens · 20 | Commander Legends: Battle for Baldur's Gate Tokens | 20 | — | — |
| Undercity TrollIconic Masters · 188 | Iconic Masters | 188 | Uncommon | €0.05 |
| Undercity TrollMagic Origins · 202 | Magic Origins | 202 | Uncommon | €0.05 |
| Undercity UpheavalMarch of the Machine: The Aftermath · 25 | March of the Machine: The Aftermath | 25 | Uncommon | €0.02 |
| Undercity UpheavalMarch of the Machine: The Aftermath · 75 | March of the Machine: The Aftermath | 75 | Uncommon | €0.03 |
| Undercity UpheavalMarch of the Machine: The Aftermath · 125 | March of the Machine: The Aftermath | 125 | Uncommon | €0.17 |
| Undercity UpheavalMarch of the Machine: The Aftermath · 205 | March of the Machine: The Aftermath | 205 | Uncommon | €0.32 |
| Undercity UprisingGuilds of Ravnica · 210 | Guilds of Ravnica | 210 | Common | €0.02 |
| Under-Construction SkyscraperMystery Booster 2 Tokens · 620 | Mystery Booster 2 Tokens | 620 | Rare | $0.21 |
| Undercover ButlerRavnica: Clue Edition · 49 | Ravnica: Clue Edition | 49 | Uncommon | $0.17 |
| Undercover CrocodelfMurders at Karlov Manor · 239 | Murders at Karlov Manor | 239 | Common | €0.05 |
| Undercover CrocodelfMurders at Karlov Manor · 239† | Murders at Karlov Manor | 239† | Common | €0.04 |
| Undercover OperativeStreets of New Capenna Promos · 63p | Streets of New Capenna Promos | 63p | Rare | €0.26 |
| Undercover OperativeStreets of New Capenna Promos · 63s | Streets of New Capenna Promos | 63s | Rare | $0.80 |
| Undercover OperativeStreets of New Capenna · 63 | Streets of New Capenna | 63 | Rare | €0.26 |
| Undercover OperativeStreets of New Capenna · 414 | Streets of New Capenna | 414 | Rare | €0.40 |
| Undercover OperativeMagic Online Promos · 99713 | Magic Online Promos | 99713 | Rare | — |
| Undercover SkrullMarvel Super Heroes · 194 | Marvel Super Heroes | 194 | Common | €0.06 |
| Underdark BasiliskAdventures in the Forgotten Realms · 208 | Adventures in the Forgotten Realms | 208 | Common | €0.11 |
| Underdark BasiliskAdventures in the Forgotten Realms · 334 | Adventures in the Forgotten Realms | 334 | Common | €0.07 |
| Underdark BasiliskAlchemy Horizons: Baldur's Gate · 227 | Alchemy Horizons: Baldur's Gate | 227 | Common | — |
| Underdark Basilisk // BasiliskAdventures in the Forgotten Realms Art Series · 9 | Adventures in the Forgotten Realms Art Series | 9 | — | — |
| Underdark BeholderMystery Booster Playtest Cards 2019 · 49 | Mystery Booster Playtest Cards 2019 | 49 | Rare | $1.65 |
| Underdark BeholderMystery Booster Playtest Cards 2021 · 49 | Mystery Booster Playtest Cards 2021 | 49 | Rare | €0.22 |
| Underdark ExplorerCommander Legends: Battle for Baldur's Gate · 154 | Commander Legends: Battle for Baldur's Gate | 154 | Common | €0.11 |
| Underdark RiftForgotten Realms Commander · 62 | Forgotten Realms Commander | 62 | Uncommon | €0.10 |
| Underdark RiftThe List Tokens · AFC-62 | The List Tokens | AFC-62 | Uncommon | €0.26 |
| Underdog RacerUnknown Event · CG05a | Unknown Event | CG05a | Common | — |
| UnderdomeUnsanctioned · 86 | Unsanctioned | 86 | Common | €0.08 |
| Underfoot UnderdogsTarkir: Dragonstorm · 129 | Tarkir: Dragonstorm | 129 | Common | €0.12 |
| Underground MortuaryMurders at Karlov Manor · 271 | Murders at Karlov Manor | 271 | Rare | €15.57 |
| Underground MortuaryMurders at Karlov Manor · 333 | Murders at Karlov Manor | 333 | Rare | €18.24 |
| Underground MortuaryMurders at Karlov Manor Promos · 271p | Murders at Karlov Manor Promos | 271p | Rare | €15.04 |
| Underground MortuaryMurders at Karlov Manor Promos · 271s | Murders at Karlov Manor Promos | 271s | Rare | €17.17 |
| Underground RiverTenth Edition · 362 | Tenth Edition | 362 | Rare | €3.74 |
| Underground RiverClassic Sixth Edition · 330 | Classic Sixth Edition | 330 | Rare | €6.68 |
| Underground RiverFifth Edition · 426 | Fifth Edition | 426 | Rare | €6.71 |
| Underground RiverSeventh Edition · 350 | Seventh Edition | 350 | Rare | €8.68 |
| Underground RiverSeventh Edition · 350★ | Seventh Edition | 350★ | Rare | $11.85 |