Arachnus Spinner

Reach
Tap an untapped Spider you control: Search your graveyard and/or library for a card named Arachnus Web and put it onto the battlefield attached to target creature. If you search your library this way, shuffle.

Silklash Spider

Reach
{X}{G}{G}: Silklash Spider deals X damage to each creature with flying.

Sentinel Spider

Spider Spawning

Create a 1/2 green Spider creature token with reach for each creature card in your graveyard.
Flashback {6}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Prey Upon

Target creature you control fights target creature you don't control. (Each deals damage equal to its power to the other.)

Mwonvuli Beast Tracker

When Mwonvuli Beast Tracker enters, search your library for a creature card with deathtouch, hexproof, reach, or trample and reveal it. Shuffle and put that card on top.

Forest

Deadly Recluse

Reach (This creature can block creatures with flying.)
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Giant Spider

Reach (This creature can block creatures with flying.)

Kessig Recluse

Swamp

Skysnare Spider

Vigilance (Attacking doesn't cause this creature to tap.)
Reach (This creature can block creatures with flying.)

Acid Web Spider

Reach
When Acid Web Spider enters, you may destroy target Equipment.

Arachnus Web

Enchant creature
Enchanted creature can't attack or block, and its activated abilities can't be activated.
At the beginning of the end step, if enchanted creature's power is 4 or greater, destroy Arachnus Web.

Stingerfling Spider

Reach
When Stingerfling Spider enters, you may destroy target creature with flying.

Overrun

Creatures you control get +3/+3 and gain trample until end of turn.

Acidic Slime

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
When Acidic Slime enters, destroy target artifact, enchantment, or land.