Boxing Day

({T}: Add {B} or {R}.) Smoldering Marsh enters tapped unless you control two or more basic lands.

{T}: Add {C}. {2}{R}, {T}: Shivan Gorge deals 1 damage to each opponent.

{1}, {T}: Add {B}{R}.

{1}, {T}: Add {G}{U}.

As Necroblossom Snarl enters, you may reveal a Swamp or Forest card from your hand. If you don't, Necroblossom Snarl enters tapped. {T}: Add {B} or...

Menace Whenever Star Athlete attacks, choose up to one target nonland permanent. Its controller may sacrifice it. If they don't, Star Athlete deals...

Hideaway 4 (When this land enters, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random ord...

{T}: Add {C}. {T}: Add {B} or {G}. Llanowar Wastes deals 1 damage to you.

Hinterland Harbor enters tapped unless you control a Forest or an Island. {T}: Add {G} or {U}.

{T}: Add {C}. {1}{W}, {T}: Put target enchantment card from your graveyard on top of your library.

{T}: Add {C}. {2}{B}{G}, {T}, Sacrifice a creature: Draw a card.

{T}: Add {C}. {B/R}, {T}: Add {B}{B}, {B}{R}, or {R}{R}.

(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.) When you u...

As Foreboding Ruins enters, you may reveal a Swamp or Mountain card from your hand. If you don't, Foreboding Ruins enters tapped. {T}: Add {B} or {R}.

{T}: Add {C}. {G/U}, {T}: Add {G}{G}, {G}{U}, or {U}{U}.

{T}: Add one mana of any color that a land an opponent controls could produce.

(Dryad Arbor isn't a spell, it's affected by summoning sickness, and it has "{T}: Add {G}.")

{T}: Add {C}. {3}: Return Drownyard Temple from your graveyard to the battlefield tapped.

Dragonskull Summit enters tapped unless you control a Swamp or a Mountain. {T}: Add {B} or {R}.

Whenever an opponent casts a noncreature spell, Gleeful Arsonist deals damage equal to its power to that player. Undying (When this creature dies, ...

{T}: Add {C}. {T}: Add {W} or {B}. Caves of Koilos deals 1 damage to you.

Castle Vantress enters tapped unless you control an Island. {T}: Add {U}. {2}{U}{U}, {T}: Scry 2.

({T}: Add {B} or {R}.) Canyon Slough enters tapped. Cycling {2} ({2}, Discard this card: Draw a card.)

Blackcleave Cliffs enters tapped unless you control two or fewer other lands. {T}: Add {B} or {R}.