Alchemist's Retrieval

Cleave {1}{U} (You may cast this spell for its cleave cost. If you do, remove the words in square brackets.)
Return target nonland permanent [you control] to its owner's hand.

Croaking Counterpart

Create a token that's a copy of target non-Frog creature, except it's a 1/1 green Frog.
Flashback {3}{G}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Tyvar's Stand

Target creature you control gets +X/+X and gains hexproof and indestructible until end of turn. (A creature with hexproof and indestructible can't be the target of spells or abilities your opponents control. Damage and effects that say "destroy" don't destroy it.)

Catlike Curiosity

Enchant creature
Enchanted creature has "Whenever this creature deals combat damage to a player, draw a card."
If Catlike Curiosity would be put into a graveyard from anywhere, exile it instead.

Mischievous Catgeist

Whenever Mischievous Catgeist deals combat damage to a player, draw a card.
Disturb {2}{U} (You may cast this card from your graveyard transformed for its disturb cost.)

Mischievous Catgeist // Catlike Curiosity

Stormchaser Drake

Flying
Whenever Stormchaser Drake becomes the target of a spell you control, draw a card.

Venerated Rotpriest

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
Whenever a creature you control becomes the target of a spell, target opponent gets a poison counter.

Forest

Dreamroot Cascade

Dreamroot Cascade enters tapped unless you control two or more other lands.
{T}: Add {G} or {U}.

Island

Serpentine Ambush

Until end of turn, target creature becomes a blue Serpent with base power and toughness 5/5.

Yavimaya Coast

{T}: Add {C}.
{T}: Add {G} or {U}. Yavimaya Coast deals 1 damage to you.

March of Swirling Mist

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.)

Tamiyo's Safekeeping

Target permanent you control gains hexproof and indestructible until end of turn. You gain 2 life. (A permanent with hexproof and indestructible can't be the target of spells or abilities your opponents control. Damage and effects that say "destroy" don't destroy it.)

Ghastly Mimicry

Enchant creature
At the beginning of your upkeep, create a token that's a copy of enchanted creature, except it's a Spirit in addition to its other types.
If Ghastly Mimicry would be put into a graveyard from anywhere, exile it instead.

Mirrorhall Mimic

You may have Mirrorhall Mimic enter as a copy of any creature on the battlefield, except it's a Spirit in addition to its other types.
Disturb {3}{U}{U} (You may cast this card from your graveyard transformed for its disturb cost.)

Mirrorhall Mimic // Ghastly Mimicry

March of Burgeoning Life

As an additional cost to cast this spell, you may exile any number of green cards from your hand. This spell costs {2} less to cast for each card exiled this way.
Choose target creature with mana value less than X. Search your library for a creature card with the same name as that creature, put it onto the battlefield tapped, then shuffle.