Partner with Toothy, Imaginary Friend (When this creature enters the battlefield, target player may put Toothy into their hand from their library, then shuffle.) If one or more counters would be put on a permanent your team controls, that many plus one of each of those kinds of counters are put on that permanent instead.

Whenever you draw a card, put a +1/+1 counter on Chasm Skulker. When Chasm Skulker dies, create X 1/1 blue Squid creature tokens with islandwalk, where X is the number of +1/+1 counters on Chasm Skulker. (They can't be blocked as long as defending player controls an Island.)

When Deepglow Skate enters the battlefield, double the number of each kind of counter on any number of target permanents.

Landfall — Whenever a land enters the battlefield under your control, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Whenever you cast a noncreature spell, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

If one or more +1/+1 counters would be put on a creature you control, that many plus one +1/+1 counters are put on it instead.

Enchant creature When Hydra's Growth enters the battlefield, put a +1/+1 counter on enchanted creature. At the beginning of your upkeep, double the number of +1/+1 counters on enchanted creature.

Whenever you cast a spell, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Commander creatures you own have "This creature enters the battlefield with an additional +1/+1 counter on it" and "Other creatures you control enter the battlefield with an additional +1/+1 counter on them."

Flying If you would proliferate, proliferate twice instead. {1}{U/P}{U/P}, Remove three counters from among other artifacts, creatures, and planeswalkers you control: Put an indestructible counter on Tekuthal, Inquiry Dominus. ({U/P} can be paid with either {U} or 2 life.)

Flying Whenever Thrummingbird deals combat damage to a player, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Put a +1/+1 counter on target creature, then double the number of +1/+1 counters on it. Flashback {8}{G}{G}. This spell costs {X} less to cast this way, where X is the greatest mana value of a commander you own on the battlefield or in the command zone. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

You have no maximum hand size. {T}: Add one mana of any color.

{T}, Discard a card: Up to one target creature can't be blocked this turn. Whenever Key to the City becomes untapped, you may pay {2}. If you do, draw a card.

{1}, {T}: Add {G}{U}.

Draw two cards. You may put a land card from your hand onto the battlefield.

When Ezuri, Stalker of Spheres enters the battlefield, you may pay {3}. If you do, proliferate twice. Whenever you proliferate, draw a card.

Evolve (Whenever a creature enters the battlefield under your control, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.) Whenever a +1/+1 counter is put on Fathom Mage, you may draw a card.

Draw a card. You may put a land card from your hand onto the battlefield.

Choose target creature you control. Whenever that creature deals combat damage to a player or planeswalker this turn, draw that many cards.

Draw cards equal to the greatest power among creatures you control. You may cast a spell with mana value 5 or less from your hand without paying its mana cost.

Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.) Draw a card.

({U/P} can be paid with either {U} or 2 life.) Draw two cards, then proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Flying {T}: Add one mana of any color.

Exile target creature you control, then return that card to the battlefield under its owner's control. Draw a card.

Exile target creature you control, then return that card to the battlefield under its owner's control. If it's a Spirit, put a +1/+1 counter on it.

Exile two target artifacts, creatures, and/or lands you control, then return those cards to the battlefield under your control.

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep. You draw a card at the beginning of the next turn's upkeep.

As an additional cost to cast this spell, you may exile any number of blue cards from your hand. This spell costs {2} less to cast for each card exiled this way. Up to X target creatures phase out. (While they're phased out, they're treated as though they don't exist. Each one phases in before its controller untaps during their next untap step.)

{T}: Add {C}. {3}{G}, {T}, Sacrifice Blighted Woodland: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

{T}: Add one mana of any color in your commander's color identity.

{T}: Add {C}. {4}: Put two +1/+1 counters on Crawling Barrens. Then you may have it become a 0/0 Elemental creature until end of turn. It's still a land.

{T}: Add {C}. {1}, {T}, Sacrifice Emergence Zone: You may cast spells this turn as though they had flash.

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

{T}, Sacrifice Fabled Passage: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Then if you control four or more lands, untap that land.

{T}: Add {C}. {G/U}, {T}: Add {G}{G}, {G}{U}, or {U}{U}.

({T}: Add {G}.)

({T}: Add {U}.)

Lumbering Falls enters the battlefield tapped. {T}: Add {G} or {U}. {2}{G}{U}: Lumbering Falls becomes a 3/3 green and blue Elemental creature with hexproof until end of turn. It's still a land.

{T}: Add {C}. {2}, {T}: Each player draws a card.

Myriad Landscape enters the battlefield tapped. {T}: Add {C}. {2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

{T}: Add {C}. {1}, {T}: Add one mana of any color in your commander's color identity. If you spend this mana to cast your commander, it enters the battlefield with a number of additional +1/+1 counters on it equal to the number of times it's been cast from the command zone this game.

You have no maximum hand size. {T}: Add {C}.

{T}: Add {C}. {4}, {T}: Target creature can't be blocked this turn.

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

As Vineglimmer Snarl enters the battlefield, you may reveal a Forest or Island card from your hand. If you don't, Vineglimmer Snarl enters the battlefield tapped. {T}: Add {G} or {U}.

Search your library for an instant or sorcery card, reveal it, then shuffle and put that card on top.

Whenever you draw a card, put a loyalty counter on Teferi, Temporal Pilgrim. 0: Draw a card. −2: Create a 2/2 blue Spirit creature token with vigilance and "Whenever you draw a card, put a +1/+1 counter on this creature." −12: Target opponent chooses a permanent they control and returns it to its owner's hand. Then they shuffle each nonland permanent they control into its owner's library.

Counter target spell.

Draw a card for each creature you control with a +1/+1 counter on it. Those creatures gain indestructible until end of turn. (Damage and effects that say "destroy" don't destroy them.)

Counter target noncreature spell.

Choose two — • Return target creature or planeswalker to its owner's hand. • Counter target artifact or enchantment spell. • Put two +1/+1 counters on target creature. • Target player shuffles up to three target cards from their graveyard into their library.

{T}: Add one mana of any color in your commander's color identity.

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

{T}: Add {G}.

Fertilid enters the battlefield with two +1/+1 counters on it. {1}{G}, Remove a +1/+1 counter from Fertilid: Target player searches their library for a basic land card, puts it onto the battlefield tapped, then shuffles.

{T}: Add {G}.

{T}: Add {G}.

When Rishkar, Peema Renegade enters the battlefield, put a +1/+1 counter on each of up to two target creatures. Each creature you control with a counter on it has "{T}: Add {G}."

{T}: Add {C}{C}.

When Eternal Witness enters the battlefield, you may return target card from your graveyard to your hand.

Put a +1/+1 counter on target creature you control if it's legendary. Then it fights target creature an opponent controls. (Each deals damage equal to its power to the other.)

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Destroy target artifact or enchantment. You may put a land card from your hand onto the battlefield.

Enchant creature, land, or planeswalker Enchanted permanent is a colorless land with "{T}: Add {C}" and loses all other card types and abilities.

Enchant creature When Kenrith's Transformation enters the battlefield, draw a card. Enchanted creature loses all abilities and is a green Elk creature with base power and toughness 3/3. (It loses all other card types and creature types.)

When Reclamation Sage enters the battlefield, you may destroy target artifact or enchantment.

Creatures you control have flying. Creatures your opponents control lose flying and can't have or gain flying.

When Duskshell Crawler enters the battlefield, put a +1/+1 counter on target creature. Each creature you control with a +1/+1 counter on it has trample.

Creatures you control with +1/+1 counters on them can't be blocked.

Reach Modified creatures you control have trample. (Equipment, Auras you control, and counters are modifications.) Whenever a modified creature you control deals combat damage to a player, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Until end of turn, creatures you control gain trample and get +X/+X, where X is the greatest power among creatures you control.

Strive — This spell costs {G} more to cast for each target beyond the first. Until end of turn, any number of target creatures each get +1/+1 and gain "{T}: This creature fights another target creature."