Krark, the Thumbless

Whenever you cast an instant or sorcery spell, flip a coin. If you lose the flip, return that spell to its owner's hand. If you win the flip, copy that spell, and you may choose new targets for the copy.
Partner (You can have two commanders if both have partner.)

Dreamshaper Shaman

At the beginning of your end step, you may pay {2}{R} and sacrifice a nonland permanent. If you do, reveal cards from the top of your library until you reveal a nonland permanent card. Put that card onto the battlefield and the rest on the bottom of your library in a random order.

Rowdy Crew

Trample
When Rowdy Crew enters, draw three cards, then discard two cards at random. If two cards that share a card type are discarded this way, put two +1/+1 counters on Rowdy Crew.

Urborg Mindsucker

{B}, Sacrifice Urborg Mindsucker: Target opponent discards a card at random. Activate only as a sorcery.

Simon, Wild Magic Sorcerer

Whenever you cast an instant or sorcery spell with mana value 3 or greater, roll a d20.
1-9 | Each player draws a card.
10-19 | You draw a card.
20 | Copy that spell. You may choose new targets for the copy.

Gamble

Search your library for a card, put that card into your hand, discard a card at random, then shuffle.

Elkin Lair

At the beginning of each player's upkeep, that player exiles a card at random from their hand. The player may play that card this turn. At the beginning of the next end step, if the player hasn't played the card, they put it into their graveyard.

Tyrant of Discord

When Tyrant of Discord enters, target opponent chooses a permanent they control at random and sacrifices it. If a nonland permanent is sacrificed this way, repeat this process.

Skullknocker Ogre

Whenever Skullknocker Ogre deals damage to an opponent, that player discards a card at random. If the player does, they draw a card.

Urza's Bauble

{T}, Sacrifice Urza's Bauble: Look at a card at random in target player's hand. You draw a card at the beginning of the next turn's upkeep.

Desperate Ravings

Draw two cards, then discard a card at random.
Flashback {2}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Jalira, Master Polymorphist

{2}{U}, {T}, Sacrifice another creature: Reveal cards from the top of your library until you reveal a nonlegendary creature card. Put that card onto the battlefield and the rest on the bottom of your library in a random order.

Neera, Wild Mage

Whenever you cast a spell, you may put it on the bottom of its owner's library. If you do, reveal cards from the top of your library until you reveal a nonland card. You may cast that card without paying its mana cost. Then put all revealed cards not cast this way on the bottom of your library in a random order. This ability triggers only once each turn.

Invert Polarity

Choose target spell, then flip a coin. If you win the flip, gain control of that spell and you may choose new targets for it. If you lose the flip, counter that spell.

Tibalt, the Fiend-Blooded

+1: Draw a card, then discard a card at random.
−4: Tibalt, the Fiend-Blooded deals damage equal to the number of cards in target player's hand to that player.
−6: Gain control of all creatures until end of turn. Untap them. They gain haste until end of turn.

Bottomless Pit

At the beginning of each player's upkeep, that player discards a card at random.

Tavern Swindler

{T}, Pay 3 life: Flip a coin. If you win the flip, you gain 6 life.

Whims of the Fates

Starting with you, each player separates all permanents they control into three piles. Then each player chooses one of their piles at random and sacrifices those permanents. (Piles can be empty.)

Gwendlyn Di Corci

{T}: Target player discards a card at random. Activate only during your turn.

Goblin Lore

Draw four cards, then discard three cards at random.

Crackling Falls

Crackling Falls enters tapped.
{T}: Add {U} or {R}.

Rush of Inspiration

Draw two cards. Then discard a card at random unless you pay {E}{E} (two energy counters).

Rush of Inspiration // Crackling Falls

Burning Inquiry

Each player draws three cards, then discards three cards at random.

Haunted Fengraf

{T}: Add {C}.
{3}, {T}, Sacrifice Haunted Fengraf: Return a creature card at random from your graveyard to your hand.

Hypnotic Specter

Flying
Whenever Hypnotic Specter deals damage to an opponent, that player discards a card at random.

Fall

Target player reveals two cards at random from their hand, then discards each nonland card revealed this way.

Rise

Return target creature card from a graveyard and target creature on the battlefield to their owners' hands.

Rise // Fall

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Reckless Handling

Search your library for an artifact card, reveal it, put it into your hand, shuffle, then discard a card at random. If an artifact card was discarded this way, Reckless Handling deals 2 damage to each opponent.

Drastic Revelation

Discard your hand. Draw seven cards, then discard three cards at random.

Spellgorger Barbarian

When Spellgorger Barbarian enters, discard a card at random.
When Spellgorger Barbarian leaves the battlefield, draw a card.

Ring of Renewal

{5}, {T}: Discard a card at random, then draw two cards.

Kindle the Carnage

Discard a card at random. If you do, Kindle the Carnage deals damage equal to that card's mana value to each creature. You may repeat this process any number of times.

Wild Magic Surge

Destroy target permanent an opponent controls. Its controller reveals cards from the top of their library until they reveal a permanent card that shares a card type with that permanent. They put that card onto the battlefield and the rest on the bottom of their library in a random order.

The Deck of Many Things

{2}, {T}: Roll a d20 and subtract the number of cards in your hand. If the result is 0 or less, discard your hand.
1—9 | Return a card at random from your graveyard to your hand.
10—19 | Draw two cards.
20 | Put a creature card from any graveyard onto the battlefield under your control. When that creature dies, its owner loses the game.

Reality Shift

Exile target creature. Its controller manifests the top card of their library. (That player puts the top card of their library onto the battlefield face down as a 2/2 creature. If it's a creature card, it can be turned face up any time for its mana cost.)