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Assembly-Worker
Atog
Aurochs
Brushwagg
Camel
Cockatrice
Dauthi Horror
Dauthi Jackal
Faerie Noble
Fungus Elemental
Fungus Sliver
Goblin Assassin
Goblin Berserker
Goblin Mutant
Goblin Wizard
Homarid Shaman
Homarid Warrior
Juggernaut
Kavu Scout
Leviathan
Lhurgoyf
Lizard Warrior
Masticore
Merfolk Assassin
Metathran Soldier
Metathran Zombie
Minotaur Warrior
Ogre Berserker
Ogre Shaman
Ogre Warrior
Orgg
Phelddagrif
Plant Elemental
Scarecrow
Shapeshifter
Skeleton Archer
Spike Drone
Thrull Wizard
Vampire Noble
Viashino Skeleton
Viashino Warrior
Zombie Assassin
Atog
Aurochs
Brushwagg
Camel
Cockatrice
Dauthi Horror
Dauthi Jackal
Faerie Noble
Fungus Elemental
Fungus Sliver
Goblin Assassin
Goblin Berserker
Goblin Mutant
Goblin Wizard
Homarid Shaman
Homarid Warrior
Juggernaut
Kavu Scout
Leviathan
Lhurgoyf
Lizard Warrior
Masticore
Merfolk Assassin
Metathran Soldier
Metathran Zombie
Minotaur Warrior
Ogre Berserker
Ogre Shaman
Ogre Warrior
Orgg
Phelddagrif
Plant Elemental
Scarecrow
Shapeshifter
Skeleton Archer
Spike Drone
Thrull Wizard
Vampire Noble
Viashino Skeleton
Viashino Warrior
Zombie Assassin
Here is a link to the same list on deckstats, if you would like to view the statistics on color distribution.
I do intend to keep this list updated, but changes are very rare. Most recently Eldraine reintroduced Noble as a creature type, retroactively adding Faerie Noble and Vampire Noble to the list. None of the cards which changed their type from Hound to Dog were relevant to this list, and none of the new creature types introduced in the last several years have been printed with a generic class name, like "Azra Ninja" or "Aetherborn Rogue" (which is probably a deliberate design choice by WotC).
One more thing to note, these cards are valid choices to name with Runed Halo, so Urza's Factory and Crib Swap and Birthing Boughs can be affected.