Swarm of Rats

Swarm of Rats's power is equal to the number of Rats you control.

Mephitic Ooze

Mephitic Ooze gets +1/+0 for each artifact you control.
Whenever Mephitic Ooze deals combat damage to a creature, destroy that creature. The creature can't be regenerated.

Junkyo Bell

At the beginning of your upkeep, you may have target creature you control get +X/+X until end of turn, where X is the number of creatures you control. If you do, sacrifice that creature at the beginning of the next end step.

Inner Calm, Outer Strength

Target creature gets +X/+X until end of turn, where X is the number of cards in your hand.

Strength of Cedars

Target creature gets +X/+X until end of turn, where X is the number of lands you control.

Nightmare Lash

Equipped creature gets +1/+1 for each Swamp you control.
Equip—Pay 3 life. (Pay 3 life: Attach to target creature you control. Equip only as a sorcery. This card enters unattached and stays on the battlefield if the creature leaves.)

Bravado

Enchant creature
Enchanted creature gets +1/+1 for each other creature you control.

Exoskeletal Armor

Enchant creature
Enchanted creature gets +X/+X, where X is the number of creature cards in all graveyards.

Vampirism

Enchant creature
When Vampirism enters, draw a card at the beginning of the next turn's upkeep.
Enchanted creature gets +1/+1 for each other creature you control.
Other creatures you control get -1/-1.

Maro

Maro's power and toughness are each equal to the number of cards in your hand.

Granite Grip

Enchant creature
Enchanted creature gets +1/+0 for each Mountain you control.

Wirewood Pride

Target creature gets +X/+X until end of turn, where X is the number of Elves on the battlefield.

Magnivore

Haste (This creature can attack and {T} as soon as it comes under your control.)
Magnivore's power and toughness are each equal to the number of sorcery cards in all graveyards.

Alpha Status

Enchant creature
Enchanted creature gets +2/+2 for each other creature on the battlefield that shares a creature type with it.