Cast into Darkness

Enchant creature
Enchanted creature gets -2/-0 and can't block.

Morgul-Knife Wound

Enchant creature
Enchanted creature gets -3/-0 and has "At the beginning of your upkeep, exile this creature unless you pay 2 life."

Greel's Caress

Flash
Enchant creature
Enchanted creature gets -3/-0.

Pin to the Earth

Enchant creature
Enchanted creature gets -6/-0.

Chant of the Skifsang

Enchant creature
Enchanted creature gets -13/-0.

Despondency

Enchant creature
Enchanted creature gets -2/-0.
When Despondency is put into a graveyard from the battlefield, return Despondency to its owner's hand.

Spontaneous Mutation

Flash
Enchant creature
Enchanted creature gets -X/-0, where X is the number of cards in your graveyard.

Torment

Enchant creature
Enchanted creature gets -3/-0.

So Tiny

Flash
Enchant creature
Enchanted creature gets -2/-0. It gets -6/-0 instead as long as its controller has seven or more cards in their graveyard.

Dwindle

Enchant creature
Enchanted creature gets -6/-0.
When enchanted creature blocks, destroy it. (The attacking creature remains blocked.)

Short Circuit

Flash
Enchant artifact or creature
As long as enchanted permanent is a creature, it gets -3/-0 and loses flying.

Sea Legs

Flash
Enchant creature
Enchanted creature gets +0/+2 as long as it's a Pirate. Otherwise, it gets -2/-0.

Tightening Coils

Enchant creature
Enchanted creature gets -6/-0 and loses flying.

Sensory Deprivation

Legacy's Allure

At the beginning of your upkeep, you may put a treasure counter on Legacy's Allure.
Sacrifice Legacy's Allure: Gain control of target creature with power less than or equal to the number of treasure counters on Legacy's Allure. (This effect lasts indefinitely.)

Shattered Ego

Enchant creature
Enchanted creature gets -3/-0.
{3}{U}{U}: Put enchanted creature into its owner's library third from the top.

Fear of Death

Enchant creature
When Fear of Death enters the battlefield, mill two cards. (Put the top two cards of your library into your graveyard.)
Enchanted creature gets -X/-0, where X is the number of cards in your graveyard.

Aether Meltdown

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature or Vehicle
When Aether Meltdown enters the battlefield, you get {E}{E} (two energy counters).
Enchanted creature gets -4/-0.

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Agoraphobia

Enchant creature
Enchanted creature gets -5/-0.
{2}{U}: Return Agoraphobia to its owner's hand.