Mountain

Grow Extra Arms

This spell costs {1} less to cast if it targets a Spider.
Target creature gets +4/+4 until end of turn.

Guy in the Chair

{T}: Add one mana of any color.
Web Support — {2}{G}, {T}: Put a +1/+1 counter on target Spider. Activate only as a sorcery.

Spider Manifestation

Reach
{T}: Add {R} or {G}.
Whenever you cast a spell with mana value 4 or greater, untap this creature.

Shock

Electro, Assaulting Battery

Flying
You don't lose unspent red mana as steps and phases end.
Whenever you cast an instant or sorcery spell, add {R}.
When Electro leaves the battlefield, you may pay {X}. When you do, he deals X damage to target player.

Vibrant Cityscape

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Web of Life and Destiny

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
At the beginning of combat on your turn, look at the top five cards of your library. You may put a creature card from among them onto the battlefield. Put the rest on the bottom of your library in a random order.

Steel Wrecking Ball

When this artifact enters, it deals 5 damage to target creature.
{1}{R}, Discard this card: Destroy target artifact.

Hobgoblin, Mantled Marauder

Flying, haste
Whenever you discard a card, Hobgoblin gets +2/+0 until end of turn.

Kraven's Last Hunt

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Mill five cards. When you do, this Saga deals damage equal to the greatest power among creature cards in your graveyard to target creature.
II — Target creature you control gets +2/+2 until end of turn.
III — Return target creature card from your graveyard to your hand.

Lurking Lizards

Trample
Whenever you cast a spell with mana value 4 or greater, put a +1/+1 counter on this creature.

Supportive Parents

Tap two untapped creatures you control: Add one mana of any color.

Multiversal Passage

As this land enters, choose a basic land type. Then you may pay 2 life. If you don't, it enters tapped.
This land is the chosen type.

Spider-Islanders

Mayhem {1}{R} (You may cast this card from your graveyard for {1}{R} if you discarded it this turn. Timing rules still apply.)

Spider-Gwen, Free Spirit

Reach
Whenever Spider-Gwen becomes tapped, you may discard a card. If you do, draw a card.

Savage Mansion

This land enters tapped.
{T}: Add {R} or {G}.
{4}, {T}: Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Forest

Electro's Bolt

Electro's Bolt deals 4 damage to target creature.
Mayhem {1}{R} (You may cast this card from your graveyard for {1}{R} if you discarded it this turn. Timing rules still apply.)

Kraven, Proud Predator

Vigilance
Top of the Food Chain — Kraven's power is equal to the greatest mana value among permanents you control.

Spider-Slayer, Hatred Honed

Whenever Spider-Slayer deals damage to a Spider, destroy that creature.
{6}, Exile this card from your graveyard: Create two tapped 1/1 colorless Robot artifact creature tokens with flying.

Spider-Rex, Daring Dino

Reach, trample
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)

Spider-Man, Brooklyn Visionary

Web-slinging {2}{G} (You may cast this spell for {2}{G} if you also return a tapped creature you control to its owner's hand.)
When Spider-Man enters, search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Rhino's Rampage

Target creature you control gets +1/+0 until end of turn. It fights target creature an opponent controls. When excess damage is dealt to the creature an opponent controls this way, destroy up to one target noncreature artifact with mana value 3 or less.

Daily Bugle Building

{T}: Add {C}.
{1}, {T}: Add one mana of any color.
Smear Campaign — {1}, {T}: Target legendary creature gains menace until end of turn. Activate only as a sorcery.