Plains

Marvin, Murderous Mimic

Marvin has all activated abilities of creatures you control that don't have the same name as this creature.

Jump Scare

Until end of turn, target creature gets +2/+2, gains flying, and becomes a Horror enchantment creature in addition to its other types.

Equipped creature gets +2/+0.
Whenever equipped creature attacks, you may sacrifice a permanent other than that creature or this Equipment. If you do, draw a card.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Maddening Hex

Enchant player
Whenever enchanted player casts a noncreature spell, roll a d6. This Aura deals damage to that player equal to the result. Then attach this Aura to another one of your opponents chosen at random.

Clockwork Percussionist

Haste
When this creature dies, exile the top card of your library. You may play it until the end of your next turn.

Grab the Prize

As an additional cost to cast this spell, discard a card.
Draw two cards. If the discarded card wasn't a land card, Grab the Prize deals 2 damage to each opponent.

Ripchain Razorkin

Reach
{2}{R}, Sacrifice a land: Draw a card.

The Jolly Balloon Man

Haste
{1}, {T}: Create a token that's a copy of another target creature you control, except it's a 1/1 red Balloon creature in addition to its other colors and types and it has flying and haste. Sacrifice it at the beginning of the next end step. Activate only as a sorcery.

Hand That Feeds

Delirium — Whenever this creature attacks while there are four or more card types among cards in your graveyard, it gets +2/+0 and gains menace until end of turn. (It can't be blocked except by two or more creatures.)

Diversion Specialist

Menace (This creature can't be blocked except by two or more creatures.)
{1}, Sacrifice another creature or enchantment: Exile the top card of your library. You may play it this turn.

Hospital Room

Whenever you attack, put a +1/+1 counter on target attacking creature.
(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.)

Surgical Suite

When you unlock this door, return target creature card with mana value 3 or less from your graveyard to the battlefield.
(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.)

Surgical Suite // Hospital Room

Fear of Immobility

When this creature enters, tap up to one target creature. If an opponent controls that creature, put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)

Mountain

Most Valuable Slayer

Whenever you attack, target attacking creature gets +1/+0 and gains first strike until end of turn.

Fear of Burning Alive

When this creature enters, it deals 4 damage to each opponent.
Delirium — Whenever a source you control deals noncombat damage to an opponent, if there are four or more card types among cards in your graveyard, this creature deals that amount of damage to target creature that player controls.

Waltz of Rage

Target creature you control deals damage equal to its power to each other creature. Until end of turn, whenever a creature you control dies, exile the top card of your library. You may play it until the end of your next turn.

Possessed Goat

{3}, Discard a card: Put three +1/+1 counters on this creature and it becomes a black Demon in addition to its other colors and types. Activate only once.

Violent Urge

Target creature gets +1/+0 and gains first strike until end of turn.
Delirium — If there are four or more card types among cards in your graveyard, that creature gains double strike until end of turn.

Sheltered by Ghosts

Enchant creature you control
When this Aura enters, exile target nonland permanent an opponent controls until this Aura leaves the battlefield.
Enchanted creature gets +1/+0 and has lifelink and ward {2}.

Bedhead Beastie

Menace (This creature can't be blocked except by two or more creatures.)
Mountaincycling {2} ({2}, Discard this card: Search your library for a Mountain card, reveal it, put it into your hand, then shuffle.)