Strixhaven: School of Mages Seeded Prerelease Booster Witherbloom has no variants:
Explore this pack in Sealed.

Sheets

Sheet common

At rate 1/30 (3.33%)
Arrogant Poet
Bayou Groff
Big Play
Blood Researcher
Charge Through
Cram Session
Crushing Disappointment
Essence Infusion
Field Trip
Hunt for Specimens
Infuse with Vitality
Lash of Malice
Leech Fanatic
Mage Duel
Mage Hunters' Onslaught
Moldering Karok
Novice Dissector
Pest Summoning
Professor of Zoomancy
Professor's Warning
Promising Duskmage
Reckless Amplimancer
Scurrid Colony
Specter of the Fens
Spined Karok
Springmane Cervin
Tangletrap
Unwilling Ingredient
Witherbloom Campus
Witherbloom Pledgemage

Sheet uncommon

At rate 1/22 (4.55%)
Bookwurm
Brackish Trudge
Containment Breach
Daemogoth Woe-Eater
Deadly Brew
Devouring Tendrils
Dina, Soul Steeper
Eyetwitch
Flunk
Fortifying Draught
Go Blank
Honor Troll
Karok Wrangler
Mage Hunter
Master Symmetrist
Mortality Spear
Necrotic Fumes
Overgrown Arch
Plumb the Forbidden
Tend the Pests
Tenured Inkcaster
Witherbloom Apprentice

Sheet rare_mythic

At rate 2/43 (4.65%)
Accomplished Alchemist
Baleful Mastery
Basic Conjuration
Callous Bloodmage
Confront the Past
Culling Ritual
Daemogoth Titan
Dragonsguard Elite
Exponential Growth
Gnarled Professor
Necroblossom Snarl
Oriq Loremage
Pestilent Cauldron
Restorative Burst
Poet's Quill
Rushed Rebirth
Sedgemoor Witch
Valentin, Dean of the Vein
Lisette, Dean of the Root
Verdant Mastery
Witherbloom Command
At rate 1/43 (2.33%)
Beledros Witherbloom
Blex, Vexing Pest
Search for Blex
Ecological Appreciation
Harness Infinity
Professor Onyx

Sheet prerelease_promo

At rate 2/159 (1.26%)
Academic Probation
Accomplished Alchemist
Archmage Emeritus
Augmenter Pugilist
Echoing Equation
Baleful Mastery
Basic Conjuration
Blade Historian
Callous Bloodmage
Codie, Vociferous Codex
Confront the Past
Conspiracy Theorist
Culling Ritual
Culmination of Studies
Daemogoth Titan
Devastating Mastery
Double Major
Draconic Intervention
Dragonsguard Elite
Dramatic Finale
Dream Strix
Efreet Flamepainter
Elemental Expressionist
Elite Spellbinder
Exponential Growth
Fervent Mastery
Flamescroll Celebrant
Revel in Silence
Frostboil Snarl
Furycalm Snarl
Gnarled Professor
Hall of Oracles
Illuminate History
Ingenious Mastery
Kianne, Dean of Substance
Imbraham, Dean of Theory
Leonin Lightscribe
Lorehold Command
Manifestation Sage
Multiple Choice
Necroblossom Snarl
Oriq Loremage
Pestilent Cauldron
Restorative Burst
Plargg, Dean of Chaos
Augusta, Dean of Order
Poet's Quill
Prismari Command
Quandrix Command
Radiant Scrollwielder
Retriever Phoenix
Rushed Rebirth
Sedgemoor Witch
Selfless Glyphweaver
Deadly Vanity
Semester's End
Shaile, Dean of Radiance
Embrose, Dean of Shadow
Shineshadow Snarl
Silverquill Command
Silverquill Silencer
Sparring Regimen
Strict Proctor
Strixhaven Stadium
Teachings of the Archaics
Tempted by the Oriq
The Biblioplex
Torrent Sculptor
Flamethrower Sonata
Uvilda, Dean of Perfection
Nassari, Dean of Expression
Valentin, Dean of the Vein
Lisette, Dean of the Root
Vanishing Verse
Venerable Warsinger
Verdant Mastery
Vineglimmer Snarl
Wandering Archaic
Explore the Vastlands
Witherbloom Command
At rate 1/159 (0.63%)
Beledros Witherbloom
Blex, Vexing Pest
Search for Blex
Blot Out the Sky
Body of Research
Crackle with Power
Ecological Appreciation
Extus, Oriq Overlord
Awaken the Blood Avatar
Galazeth Prismari
Harness Infinity
Hofri Ghostforge
Jadzi, Oracle of Arcavios
Journey to the Oracle
Kasmina, Enigma Sage
Magma Opus
Mascot Exhibition
Mavinda, Students' Advocate
Mila, Crafty Companion
Lukka, Wayward Bonder
Professor Onyx
Rowan, Scholar of Sparks
Will, Scholar of Frost
Shadrix Silverquill
Tanazir Quandrix
Velomachus Lorehold