Exotic Pets

Create two 1/1 blue Fish creature tokens with "This token can't be blocked." Then for each kind of counter among creatures you control, put a counter of that kind on either of those tokens.

Security Bypass

Enchant creature
As long as enchanted creature is attacking alone, it can't be blocked.
Enchanted creature has "Whenever this creature deals combat damage to a player, it connives." (Its controller draws a card, then discards a card. If they discarded a nonland card, they put a +1/+1 counter on this creature.)

Forest

Cabaretti Initiate

{2}{R/W}: This creature gains double strike until end of turn.

Majestic Metamorphosis

Until end of turn, target artifact or creature becomes a 4/4 Angel artifact creature and gains flying.
Draw a card.

Broken Wings

Destroy target artifact, enchantment, or creature with flying.

Island

Lagrella, the Magpie

When Lagrella enters, exile any number of other target creatures controlled by different players until Lagrella leaves the battlefield. When an exiled card enters under your control this way, put two +1/+1 counters on it.

Rhox Pummeler

This creature enters with a shield counter on it. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)
This creature has trample as long as it has a shield counter on it.

Metropolis Angel

Flying
Whenever you attack with one or more creatures with counters on them, draw a card.

Illuminator Virtuoso

Double strike
Whenever this creature becomes the target of a spell you control, it connives. (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on this creature.)

Knockout Blow

This spell costs {2} less to cast if it targets a red creature.
Knockout Blow deals 4 damage to target attacking or blocking creature and you gain 2 life.

Plains

Botanical Plaza

This land enters tapped.
{T}: Add {G} or {W}.
{2}{G}{W}, {T}, Sacrifice this land: Draw a card.

Out of the Way

This spell costs {2} less to cast if it targets a green permanent.
Return target nonland permanent an opponent controls to its owner's hand.
Draw a card.

Faerie Vandal

Flash (You may cast this spell any time you could cast an instant.)
Flying
Whenever you draw your second card each turn, put a +1/+1 counter on this creature.

Disciplined Duelist

Double strike
This creature enters with a shield counter on it. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)

Brokers Hideout

When this land enters, sacrifice it. When you do, search your library for a basic Forest, Plains, or Island card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Caldaia Strongarm

When this creature enters, put two +1/+1 counters on target creature.
Blitz {3}{G} (If you cast this spell for its blitz cost, it gains haste and "When this creature dies, draw a card." Sacrifice it at the beginning of the next end step.)

Backup Agent

When this creature enters, put a +1/+1 counter on target creature.

Skybridge Towers

This land enters tapped.
{T}: Add {W} or {U}.
{2}{W}{U}, {T}, Sacrifice this land: Draw a card.

Boon of Safety

Put a shield counter on target creature. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)
Scry 1.

Slip Out the Back

Put a +1/+1 counter on target creature. It phases out. (Treat it and anything attached to it as though they don't exist until its controller's next turn.)

Voice of the Vermin

This creature enters with a shield counter on it. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)
Whenever this creature attacks, target creature you control has base power and toughness 4/4 until end of turn.

Psychic Pickpocket

When this creature enters, it connives. When it connives this way, return up to one target nonland permanent to its owner's hand. (To have a creature connive, draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on that creature.)

Wingshield Agent

This creature enters with a shield counter on it. (If it would be dealt damage or destroyed, remove a shield counter from it instead.)
Whenever this creature attacks, up to one other target creature gains flying until end of turn.