Costume Closet

This artifact enters with two +1/+1 counters on it.
{T}: Move a +1/+1 counter from this artifact onto target creature you control. Activate only as a sorcery.
Whenever a modified creature you control leaves the battlefield, put a +1/+1 counter on this artifact. (Equipment, Auras you control, and counters are modifications.)

Biorganic Carapace

When this Equipment enters, attach it to target creature you control.
Equipped creature gets +2/+2 and has "Whenever this creature deals combat damage to a player, draw a card for each modified creature you control." (Equipment, Auras you control, and counters are modifications.)
Equip {2}

SP//dr, Piloted by Peni

Vigilance
When SP//dr enters, put a +1/+1 counter on target creature.
Whenever a modified creature you control deals combat damage to a player, draw a card. (Equipment, Auras you control, and counters are modifications.)

Wraith, Vicious Vigilante

Double strike
Fear Gas — Wraith can't be blocked.

Rocket-Powered Goblin Glider

When this Equipment enters, if it was cast from your graveyard, attach it to target creature you control.
Equipped creature gets +2/+0 and has flying and haste.
Equip {2}
Mayhem {2}

Island

Doc Ock's Tentacles

Whenever a creature you control with mana value 5 or greater enters, you may attach this Equipment to it.
Equipped creature gets +4/+4.
Equip {5}

With Great Power...

Enchant creature you control
Enchanted creature gets +2/+2 for each Aura and Equipment attached to it.
All damage that would be dealt to you is dealt to enchanted creature instead.

Web-Shooters

Equipped creature gets +1/+1 and has reach and "Whenever this creature attacks, tap target creature an opponent controls."
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Plains

Friendly Neighborhood

Enchant land
When this Aura enters, create three 1/1 green and white Human Citizen creature tokens.
Enchanted land has "{1}, {T}: Target creature gets +1/+1 until end of turn for each creature you control. Activate only as a sorcery."

Spider-Woman, Stunning Savior

Flying
Venom Blast — Artifacts and creatures your opponents control enter tapped.

Sun-Spider, Nimble Webber

During your turn, Sun-Spider has flying.
When Sun-Spider enters, search your library for an Aura or Equipment card, reveal it, put it into your hand, then shuffle.

Spider-Suit

Equipped creature gets +2/+2 and is a Spider Hero in addition to its other types.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Silver Sable, Mercenary Leader

When Silver Sable enters, put a +1/+1 counter on another target creature.
Whenever Silver Sable attacks, target modified creature you control gains lifelink until end of turn. (Equipment, Auras you control, and counters are modifications.)

Robotics Mastery

Flash
Enchant creature
When this Aura enters, create two 1/1 colorless Robot artifact creature tokens with flying.
Enchanted creature gets +2/+2.

Skyward Spider

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
This creature has flying as long as it's modified. (Equipment, Auras you control, and counters are modifications.)