Michelangelo, the Heart

Trample
Raid (the Fridge) — At the beginning of your second main phase, if you attacked this turn, put a +1/+1 counter on target creature and create a Food token.
Partner—Character select (You can have two commanders if both have this ability.)

Mona Lisa, Ever Adaptable

Whenever a player casts a creature spell, you create a Mutagen token. (It's an artifact with "{1}, {T}, Sacrifice this token: Put a +1/+1 counter on target creature. Activate only as a sorcery.")

Mutagen Man, Living Ooze

Trample
Activated abilities of artifact tokens you control cost {1} less to activate.
When Mutagen Man enters, create X Mutagen tokens. (They're artifacts with "{1}, {T}, Sacrifice this token: Put a +1/+1 counter on target creature. Activate only as a sorcery.")

Prishe's Wanderings

Search your library for a basic land card or Town card, put it onto the battlefield tapped, then shuffle. When you search your library this way, put a +1/+1 counter on target creature you control.

Sazh Katzroy

When Sazh Katzroy enters, you may search your library for a Bird or basic land card, reveal it, put it into your hand, then shuffle.
Whenever Sazh Katzroy attacks, put a +1/+1 counter on target creature, then double the number of +1/+1 counters on that creature.

Atmospheric Greenhouse

When this Spacecraft enters, put a +1/+1 counter on each creature you control.
Station (Tap another creature you control: Put charge counters equal to its power on this Spacecraft. Station only as a sorcery. It's an artifact creature at 8+.)
8+ | Flying, trample

Evolution Sage

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

Galuf's Final Act

Until end of turn, target creature gets +1/+0 and gains "When this creature dies, put a number of +1/+1 counters equal to its power on up to one target creature."

Michelangelo, On the Scene

Trample (This creature can deal excess combat damage to the player it's attacking.)
Michelangelo enters with a +1/+1 counter on him for each land you control.
When Michelangelo dies, return this card to your hand.

Solid Ground

When this enchantment enters, earthbend 3. (Target land you control becomes a 0/0 creature with haste that's still a land. Put three +1/+1 counters on it. When it dies or is exiled, return it to the battlefield tapped.)
If one or more +1/+1 counters would be put on a permanent you control, that many plus one +1/+1 counters are put on it instead.

Yuna's Whistle

Reveal cards from the top of your library until you reveal a creature card. Put that card into your hand and the rest on the bottom of your library in a random order. When you reveal a creature card this way, put X +1/+1 counters on target creature you control, where X is the mana value of that card.

Silkguard

Put a +1/+1 counter on each of up to X target creatures you control.
Auras, Equipment, and modified creatures you control gain hexproof until end of turn. (Equipment, Auras you control, and counters are modifications.)

Leatherhead, Swamp Stalker

Trample
Leatherhead enters with a hexproof counter on her.
Whenever Leatherhead deals combat damage to a player, you may remove a counter from her. When you do, destroy target artifact or enchantment that player controls.

Seismic Tutelage

Enchant creature
When this Aura enters, put a +1/+1 counter on enchanted creature.
Whenever enchanted creature attacks, double the number of +1/+1 counters on it.

Match the Odds

Create a 1/1 white Ally creature token. Put a +1/+1 counter on it for each creature your opponents control.

Voracious Hydra

Trample
This creature enters with X +1/+1 counters on it.
When this creature enters, choose one —
• Double the number of +1/+1 counters on this creature.
• This creature fights target creature you don't control.

Devoted Druid

{T}: Add {G}.
Put a -1/-1 counter on this creature: Untap this creature.

Rocksteady, Mutant Marauder

Partner with Bebop, Skull & Crossbones (When this creature enters, target player may put Bebop into their hand from their library, then shuffle.)
Trample
Whenever another nontoken creature you control enters, put a +1/+1 counter on target creature.

Strength of Will

Until end of turn, target creature you control gains indestructible and "Whenever this creature is dealt damage, put that many +1/+1 counters on it."

Loading Zone

If one or more counters would be put on a creature, Spacecraft, or Planet you control, twice that many of each of those kinds of counters are put on it instead.
Warp {G} (You may cast this card from your hand for its warp cost. Exile this enchantment at the beginning of the next end step, then you may cast it from exile on a later turn.)

Hemosymbic Mite

Whenever this creature becomes tapped, another target creature you control gets +X/+X until end of turn, where X is this creature's power.

Michelangelo, Weirdness to 11

When Michelangelo enters, create a Mutagen token. (It's an artifact with "{1}, {T}, Sacrifice this token: Put a +1/+1 counter on target creature. Activate only as a sorcery.")
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.

Mikey & Mona, Mutant Sitters

When Mikey & Mona enter, choose one or both. Each mode must target a different player.
• Target player chooses a creature they control and puts two +1/+1 counters on it.
• Target player returns a creature or land card from their graveyard to their hand.

Steelbane Hydra

This creature enters with X +1/+1 counters on it.
{2}{G}, Remove a +1/+1 counter from this creature: Destroy target artifact or enchantment.

Titan of Industry

Reach, trample
When this creature enters, choose two —
• Destroy target artifact or enchantment.
• Target player gains 5 life.
• Create a 4/4 green Rhino Warrior creature token.
• Put a shield counter on a creature you control.

Puca's Covenant

Whenever a creature you control with a counter on it dies, you may return another target permanent card with mana value less than or equal to the number of counters on that creature from your graveyard to your hand. Do this only once each turn.

Study the Classics

Put a +1/+1 counter on target creature, then double the number of +1/+1 counters on it. You gain life equal to the number of +1/+1 counters on that creature.

Toph, Earthbending Master

Landfall — Whenever a land you control enters, you get an experience counter.
Whenever you attack, earthbend X, where X is the number of experience counters you have. (Target land you control becomes a 0/0 creature with haste that's still a land. Put X +1/+1 counters on it. When it dies or is exiled, return it to the battlefield tapped.)

Earthbender Ascension

When this enchantment enters, earthbend 2. Then search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Landfall — Whenever a land you control enters, put a quest counter on this enchantment. When you do, if it has four or more quest counters on it, put a +1/+1 counter on target creature you control. It gains trample until end of turn.

Inspiring Call

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.)

Beastmaster Ascension

Whenever a creature you control attacks, you may put a quest counter on this enchantment.
As long as this enchantment has seven or more quest counters on it, creatures you control get +5/+5.

Ride the Shoopuf

Landfall — Whenever a land you control enters, put a +1/+1 counter on target creature you control.
{5}{G}{G}: This enchantment becomes a 7/7 Beast creature in addition to its other types.

Tale of Katara and Toph

Creatures you control have "Whenever this creature becomes tapped for the first time during each of your turns, put a +1/+1 counter on it."

Ferrafor, Young Yew

When Ferrafor enters, create a number of 1/1 green Saproling creature tokens equal to the number of counters among creatures target player controls.
{T}: Double the number of each kind of counter on target creature.

Animal Attendant

{T}: Add one mana of any color. If that mana is spent to cast a non-Human creature spell, that creature enters with an additional +1/+1 counter on it.

Avatar Kyoshi, Earthbender

During your turn, Avatar Kyoshi has hexproof.
At the beginning of combat on your turn, earthbend 8, then untap that land. (Target land you control becomes a 0/0 creature with haste that's still a land. Put eight +1/+1 counters on it. When it dies or is exiled, return it to the battlefield tapped.)

Broodguard Elite

This creature enters with X +1/+1 counters on it.
When this creature leaves the battlefield, put its counters on target creature you control.
Warp {X}{G} (You may cast this card from your hand for its warp cost. Exile this creature at the beginning of the next end step, then you may cast it from exile on a later turn.)

Terrasymbiosis

Whenever you put one or more +1/+1 counters on a creature you control, you may draw that many cards. Do this only once each turn.

Level Up

Enchant creature
When this Aura enters, put a +1/+1 counter on enchanted creature.
Enchanted creature has "Whenever this creature attacks, double the number of +1/+1 counters on it. Then if it has power 10 or greater, draw a card."

Spider-Man, Miles Morales

Vigilance, trample (Attacking doesn't cause this creature to tap. He can deal excess combat damage to the player he's attacking.)
Whenever Spider-Man enters or attacks, put a +1/+1 counter on each other creature you control. Those creatures gain trample until end of turn.