Shrieking Drake

Flying
When this creature enters, return a creature you control to its owner's hand.

Spore Frog

Sacrifice this creature: Prevent all combat damage that would be dealt this turn.

Skyskipper Duo

Flying
When this creature enters, exile up to one other target creature you control. Return it to the battlefield under its owner's control at the beginning of the next end step.

Vanquisher's Banner

As this artifact enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
Whenever you cast a creature spell of the chosen type, draw a card.

Dour Port-Mage

Whenever one or more other creatures you control leave the battlefield without dying, draw a card.
{1}{U}, {T}: Return another target creature you control to its owner's hand.

Peregrine Drake

Flying
When this creature enters, untap up to five lands.

Twenty-Toed Toad

Your maximum hand size is twenty.
Whenever you attack with two or more creatures, put a +1/+1 counter on Twenty-Toed Toad and draw a card.
Whenever Twenty-Toed Toad attacks, you win the game if there are twenty or more counters on it or you have twenty or more cards in hand.

Polliwallop

Affinity for Frogs (This spell costs {1} less to cast for each Frog you control.)
Target creature you control deals damage equal to twice its power to target creature you don't control.

Breeding Pool

({T}: Add {G} or {U}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Intruder Alarm

Creatures don't untap during their controllers' untap steps.
Whenever a creature enters, untap all creatures.

Beast Whisperer

Whenever you cast a creature spell, draw a card.

Yavimaya Coast

{T}: Add {C}.
{T}: Add {G} or {U}. This land deals 1 damage to you.

Pond Prophet

Clement, the Worrywort

Vigilance
Whenever Clement or another creature you control enters, return up to one target creature you control with lesser mana value to its owner's hand.
Frogs you control have "{T}: Add {G} or {U}. Spend this mana only to cast a creature spell."

Species Gorger

At the beginning of your upkeep, return a creature you control to its owner's hand.

Talisman of Curiosity

{T}: Add {C}.
{T}: Add {G} or {U}. This artifact deals 1 damage to you.

Sunshower Druid

When this creature enters, put a +1/+1 counter on target creature and you gain 1 life.

Haze Frog

Flash (You may cast this spell any time you could cast an instant.)
When this creature enters, prevent all combat damage that other creatures would deal this turn.

Long River Lurker

Ward {1}
Other Frogs you control have ward {1}.
When this creature enters, target creature you control can't be blocked this turn. Whenever that creature deals combat damage this turn, you may exile it. If you do, return it to the battlefield under its owner's control.

Treeguard Duo

When this creature enters, until end of turn, target creature you control gains vigilance and gets +X/+X, where X is the number of creatures you control.

Valley Mightcaller

Trample
Whenever another Frog, Rabbit, Raccoon, or Squirrel you control enters, put a +1/+1 counter on this creature.

Papercraft Decoy

When this creature leaves the battlefield, you may pay {2}. If you do, draw a card.

Arcane Signet

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

Forest

Into the Flood Maw

Gift a tapped Fish (You may promise an opponent a gift as you cast this spell. If you do, they create a tapped 1/1 blue Fish creature token before its other effects.)
Return target creature an opponent controls to its owner's hand. If the gift was promised, instead return target nonland permanent an opponent controls to its owner's hand.

Candlekeep Sage

Commander creatures you own have "When this creature enters or leaves the battlefield, draw a card."

Sol Ring

Lilysplash Mentor

Reach
{1}{G}{U}: Exile another target creature you control, then return it to the battlefield under its owner's control with a +1/+1 counter on it. Activate only as a sorcery.

Kindred Discovery

As this enchantment enters, choose a creature type.
Whenever a creature you control of the chosen type enters or attacks, draw a card.

Mistbreath Elder

At the beginning of your upkeep, return another creature you control to its owner's hand. If you do, put a +1/+1 counter on this creature. Otherwise, you may return this creature to its owner's hand.

Command Tower

Reliquary Tower

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

Reflections of Littjara

As this enchantment enters, choose a creature type.
Whenever you cast a spell of the chosen type, copy that spell. (A copy of a permanent spell becomes a token.)