Bashful Beastie

When Bashful Beastie dies, manifest dread. (Look at the top two cards of your library. Put one onto the battlefield face down as a 2/2 creature and the other into your graveyard. Turn it face up any time for its mana cost if it's a creature card.)

Miasma Demon

Flying
When Miasma Demon enters, you may discard any number of cards. When you do, up to that many target creatures each get -2/-2 until end of turn.

Leyline of Mutation

If Leyline of Mutation is in your opening hand, you may begin the game with it on the battlefield.
You may pay {W}{U}{B}{R}{G} rather than pay the mana cost for spells you cast.

Oblivious Bookworm

At the beginning of your end step, you may draw a card. If you do, discard a card unless a permanent entered the battlefield face down under your control this turn or you turned a permanent face up this turn.

Overlord of the Hauntwoods

Impending 4—{1}{G}{G} (If you cast this spell for its impending cost, it enters with four time counters and isn't a creature until the last is removed. At the beginning of your end step, remove a time counter from it.)
Whenever Overlord of the Hauntwoods enters or attacks, create a tapped colorless land token named Everywhere that is every basic land type.

Island

Lakeside Shack

Lakeside Shack enters tapped unless a player has 13 or less life.
{T}: Add {G} or {U}.

Cursed Windbreaker

When Cursed Windbreaker enters, manifest dread, then attach Cursed Windbreaker to that creature. (Look at the top two cards of your library. Put one onto the battlefield face down as a 2/2 creature and the other into your graveyard. Turn it face up any time for its mana cost if it's a creature card.)
Equipped creature has flying.
Equip {3}

Flesh Burrower

Deathtouch
Whenever Flesh Burrower attacks, another target creature you control gains deathtouch until end of turn.

Unable to Scream

Enchant creature
Enchanted creature loses all abilities and is a Toy artifact creature with base power and toughness 0/2 in addition to its other types.
As long as enchanted creature is face down, it can't be turned face up.

Coordinated Clobbering

Tap one or two target untapped creatures you control. They each deal damage equal to their power to target creature an opponent controls.

Cautious Survivor

Survival — At the beginning of your second main phase, if Cautious Survivor is tapped, you gain 2 life.

Erratic Apparition

Flying, vigilance
Eerie — Whenever an enchantment you control enters and whenever you fully unlock a Room, Erratic Apparition gets +1/+1 until end of turn.

Fractured Realm

If a triggered ability of a permanent you control triggers, that ability triggers an additional time.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Mirror Room

When you unlock this door, create a token that's a copy of target creature you control, except it's a Reflection in addition to its other creature types.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Mirror Room // Fractured Realm

Tunnel Surveyor

When Tunnel Surveyor enters, create a 1/1 white Glimmer enchantment creature token.

Vanish from Sight

Target nonland permanent's owner puts it on their choice of the top or bottom of their library. Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

House Cartographer

Survival — At the beginning of your second main phase, if House Cartographer is tapped, reveal cards from the top of your library until you reveal a land card. Put that card into your hand and the rest on the bottom of your library in a random order.

Anthropede

Reach
When Anthropede enters, you may discard a card or pay {2}. When you do, destroy target Room.

Say Its Name

Mill three cards. Then you may return a creature or land card from your graveyard to your hand.
Exile this card and two other cards named Say Its Name from your graveyard: Search your graveyard, hand, and/or library for a card named Altanak, the Thrice-Called and put it onto the battlefield. If you search your library this way, shuffle. Activate only as a sorcery.

Forest

Rootwise Survivor

Haste
Survival — At the beginning of your second main phase, if Rootwise Survivor is tapped, put three +1/+1 counters on up to one target land you control. That land becomes a 0/0 Elemental creature in addition to its other types. It gains haste until your next turn.

Bear Trap

Flash
{3}, {T}, Sacrifice Bear Trap: It deals 3 damage to target creature.

Fear of Failed Tests

Whenever Fear of Failed Tests deals combat damage to a player, draw that many cards.

Frantic Strength

Flash
Enchant creature
Enchanted creature gets +2/+2 and has trample.

Horrid Vigor

Target creature gains deathtouch and indestructible until end of turn.

Stay Hidden, Stay Silent

Enchant creature
When Stay Hidden, Stay Silent enters, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.
{4}{U}{U}: Shuffle enchanted creature into its owner's library, then manifest dread. Activate only as a sorcery.

Enter the Enigma

Target creature can't be blocked this turn.
Draw a card.

Attack-in-the-Box

Whenever Attack-in-the-Box attacks, you may have it get +4/+0 until end of turn. If you do, sacrifice it at the beginning of the next end step.

Tyvar, the Pummeler

Tap another untapped creature you control: Tyvar, the Pummeler gains indestructible until end of turn. Tap it.
{3}{G}{G}: Creatures you control get +X/+X until end of turn, where X is the greatest power among creatures you control.

Don't Make a Sound

Counter target spell unless its controller pays {2}. If they do, surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Wary Watchdog

When Wary Watchdog enters or dies, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Glimmerburst

Draw two cards. Create a 1/1 white Glimmer enchantment creature token.

Daggermaw Megalodon

Vigilance
Islandcycling {2} ({2}, Discard this card: Search your library for an Island card, reveal it, put it into your hand, then shuffle.)

Malevolent Chandelier

Flying
{2}: Put target card from a graveyard on the bottom of its owner's library. Activate only as a sorcery.