MTG Arena’s collection of cards has always been a somewhat controversial point amongst the community. Many of Magic’s paper formats simply aren’t playable on the client because too many key cards are missing. Explorer is a great example of this. The format has improved upon its original mission of becoming Pioneer on MTG Arena, but the format is still missing some key cards preventing some decks from being viable on the client. You can find those cards here.
Considering how problematic MTG Arena’s card collection is, it may be shocking to hear that there are some cards on the platform that players don’t even have the option to craft! Thanks to the Spellbook mechanic within Alchemy, there are quite a few of these cards on Arena. Miraculously, however, even more nigh unplayable cards have been discovered recently thanks to Arena’s most frustrating format: Momir!
Momir’s Madness
MTG players who love absolute chaos in its truest sense likely have an affinity for the Momir format. Your entire deck is basic lands, and each player gets an emblem that can be used once per turn. This emblem randomly generates a creature with an equal mana value to the amount invested. This means you could end up playing with any creature on the entire platform!
This, in itself, has its own issues. Investing six mana could get an unlucky player a copy of
Demonlord Belzenlok

When Demonlord Belzenlok enters, exile cards from the top of your library until you exile a nonland card, then put that card into your hand. If the card's mana value is 4 or greater, repeat this process. Demonlord Belzenlok deals 1 damage to you for each card put into your hand this way.
. Because your entire deck is basic lands, Belzonlok’s ETB trigger will kill you by decking you out. Events like this can make trying to strategize in Momir formats rather frustrating.
Interestingly, there if you invest larger amounts of mana into your emblem, you can actually acquire some otherwise unplayable creatures! These cards are only available in the Momir format but could be perfectly playable in other formats like Historic or Timeless. What are these cards, and why can’t we craft them?
MTG Arena’s Mysterious Monsters

Unlike many of MTG Arena’s current formats, the Momir’s Madness format has existed since the beginning. Even though players complain about MTG Arena’s current card pool, it was even smaller back in the early days of the client.
This created a big problem for the Momir format. Any time players got to larger mana values in the format, they were almost guaranteed to get specific cards.
Zacama, Primal Calamity

When Zacama enters, if you cast it, untap all lands you control.
{2}{R}: Zacama deals 3 damage to target creature.
{2}{G}: Destroy target artifact or enchantment.
{2}{W}: You gain 3 life.
, for example, was an overwhelmingly common card to get when investing nine mana. As a result, Wizards of the Coast decided to add new, uncraftable, creatures to MTG Arena to make Momir more exciting.
Since the format doesn’t come around all too often, these unusual cards were quickly forgotten about over the years. Now that Momir is back for the moment, however, these curious cards are popping up once again. Bringer of the Blue Dawn, for example, was recently discovered to be one of the previously added Momir cards thanks to a recent Reddit post.
Unfortunately, there is no up-to-date list of cards that are exclusively available for the Momir format on MTG Arena. The closest we have is this three-year-old list which covers some curious old additions. Bolstering this selection, it seems a number of new discoveries have popped up online recently within Momir matches. Some of these cards could even be playable in formats like Explorer.
Read More: Returning $80 Strategy Dominates Massive MTG Event!
Borborygmos, Enraged

Borborygmos, Enraged does see some occasional play in Pioneer, which means it could be a role player in the Explorer format. This is thanks to
Possibility Storm

By using an Adventure Sorcery, while only having one other Sorcery available in your deck, Possibility Storm makes it so your Sorcery will always become that Sorcery since it does not recognize Adventure cards as Instants or Sorceries. You can use this to cast a cheap
Enter the Infinite

Iona, Shield of Emeria

Iona, Shield of Emeria is another card that could have some applications in decks that can cheat creatures out. This could be an alternative win condition for
Indomitable Creativity

Read More: Insane Political EDH Powerhouses Can Offer Triple Value!
Tidespout Tyrant

Tidespout Tyrant is an eight mana creature that could easily become a win condition in any deck capable of cheating it into play.
Hullbreaker Horror

This spell can't be countered.
Whenever you cast a spell, choose up to one —
• Return target spell you don't control to its owner's hand.
• Return target nonland permanent to its owner's hand.
offers a very similar ability that is strictly better than the Tyrant, but having another option could be beneficial for the right MTG deck.
Blazing Archon

Creatures can’t attack you is a very fun line of text. Blazing Archon prevents your opponents from even attempting to swing their creatures in your direction. Sure, this probably isn’t strong enough to be playable in formats like Historic or Timeless, but it could be a fun inclusion to Historic Brawl decks!
Why Aren’t These Cards Craftable?
If these MTG cards are already coded into the client, why can’t players just craft them to use? Some comments suggest that the MTG developers don’t like making cards available to players without some other way to acquire them that doesn’t involve directly using wildcards. We have no way to confirm whether this is true or not, but the policy makes sense.
Either way, a majority of the Momir’s Madness exclusives don’t have a ton of uses on the client anymore. Some cards that were originally added as part of the Momir format have since been printed in sets and are available for players to craft, like
Ulamog, the Ceaseless Hunger

Indestructible
Whenever Ulamog attacks, defending player exiles the top twenty cards of their library.
.
The cards above do not include all of the ones exclusively available on MTG Arena’s Momir format. Here are all the other cards that we know about, but there are likely even more to discover.
-
Demon of Death’s Gate
Demon of Death’s Gate You may pay 6 life and sacrifice three black creatures rather than pay this spell's mana cost.
Flying, trample -
Fire Dragon
Fire Dragon Flying
When this creature enters, it deals damage to target creature equal to the number of Mountains you control. - Thing in the Deep
-
Furnace Dragon
Furnace Dragon Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Flying
When this creature enters, if you cast it from your hand, exile all artifacts. -
Kuro, Pitlord
Kuro, Pitlord At the beginning of your upkeep, sacrifice Kuro unless you pay {B}{B}{B}{B}.
Pay 1 life: Target creature gets -1/-1 until end of turn. -
Colossus of Sardia
Colossus of Sardia Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
This creature doesn't untap during your untap step.
{9}: Untap this creature. Activate only during your upkeep. -
Gigantomancer
Gigantomancer {1}: Target creature you control has base power and toughness 7/7 until end of turn.
-
Crash of Rhinos
Crash of Rhinos Trample
- Baleful Force
- Scaled Wurm
- Hoverguard Sweepers
- Dragon Tyrant
- Stratadon
- Dread Cacodemon
Due to the number of spells on MTG Arena, it’s possible that more uncraftable spells are lurking within the client. Over time, as more and more Momir’s Madness is played, more of these cards are likely to emerge. Whether or not this will happen, however, remains to be seen, as there’s no telling how many cards are still left to be found.
Read More: These MTG Hidden Gems for Your Sideboard are Extremely Underrated!