Fear of Looking Stupid
Enchantment Creature — Nightmare (R)
Vigilance
Whenever a spell or ability you control counters a spell an opponent controls, exile that spell.
Whenever Fear of Looking Stupid deals combat damage to an opponent, you may cast a card that opponent owns that was exiled with this creature without paying its mana cost.
3/3

Fear of the Depths

Enchantment Creature -- Nightmare (M)
At the beginning of each player’s upkeep, that player chooses a creature they control and puts it on the bottom of their library.
Laren's fear of the deep ocean stemmed partially from the fear of the unknown. Learning what was down there, as it turned out, did nothing to lessen that fear.
7/7

Fear of Forgetting

Enchantment Creature - Nightmare (C)
When this creature enters, each opponent discards a card.
The only thing worse than the feeling of dread when the word slips from your mind is the feeling of embarrassment as you freeze in front of your expectant audience.
2/2

Fear of Disease

Enchantment Creature - Nightmare {U}
When Fear of Disease enters the battlefield or attacks, put a -1/-1 counter on up to one target creature.
3/3

Fear of Rats

Enchantment Creature - Nightmare (R)
At the beginning of your upkeep, create a 1/1 black Rat creature token with deathtouch.
"Dirty, smelly, sharp claws. What's not to like?"
—Liliana Vess
3/3

Fear of Death
Enchantment Creature ─ Nightmare (M)
Menace
When Fear of Death enters, destroy target creature.
At the beginning of your upkeep, if there are no creatures on the battlefield, return Fear of Death from your graveyard to your hand.
4/4

Fear of Thunderstorms

Enchantment Creature - Nightmare (C)
When this creature enters, it deals 2 damage to any target.
As Priya pulled her shawl around herself, the forked lightning flashed across the sky in the distance. Although she couldn't be sure, Priya could swear it had formed a face. It was as if the storm was smiling at her... watching her... jeering at her...
2/1

That is an insane limited card.

Fear of Needles

Enchantment Creature -- Nightmare (U)
First strike
When Fear of Needles enters, it deals 1 damage to any target.
Whenever a source you control deals exactly 1 damage to a player or permanent, put a +1/+1 counter on Fear of Needles.
1/1

Fear of Heights
Enchantment Creature - Nightmare {R}
: Fear of Heights deals 1 damage to any target.
Whenever a creature with flying dies, Fear of Heights deals 1 damage to each creature with flying and each player.
3/3

Mythic common.

Fear of Monotony
Enchantment Creature — Nightmare (M)
Haste
Whenever you cast or copy a spell that doesn't share a name with a spell you cast this game, exile the top two cards on your library. You may cast up to one of them until the end of your next turn.
4/4

Fear of Spiders
Enchantment Creature ─ Nightmare (C)
Reach, skulk
1/1

Fear of Exposure
Enchantment Creature - Nightmare (U)
Landfall - Whenever a land you control enters, target creature you control gains deathtouch until end of turn.
Infinite walls, a plane-spanning roof, and zero shelter.
1/3

Whoops! I accidently merged my first thought and my second thought without deleting my first thought. I have now removed first strike. I also downed the damage from 3 to 2 on reflection and looking up similar current cards. Hopefully this makes me look slightly less silly!

Also, @neru: Fear of Exposure

Fear of Snakes

Enchantment Creature - Nightmare (R)
Whenever a land you control enters, create a 1/1 green Snake creature token. If that land is a Forest, put a deathtouch counter on that creature token.
Sara knew the difference between venomous and poisonous snakes, and this one wasn't venomous, however that didn't help her feel any more calm about the prospect of it slithering around her feet...
4/4

Yeah the current version, a 2/1 for 3 that shocks, is solid but not that much past Fire Imp, which is REALLY old.

Fear of Predators

Enchantment Creature - Nightmare {M}
Whenever a creature enters under an opponent's control, create a 3/3 green nightmare beast enchantment creature token. It fights that creature.
4/4

I even had one in my last DSK draft deck.

Fear of Ninjas
Enchantment Creature - Nightmare (C)
When this creature leaves the battlefield, target opponent discards a card.
It is never just a shadow.
1/1

Fear of Fear Itself

Enchantment Creature - Nightmare {U}
Menace
Other Nightmares you control have Menace
Nightmare spells you cast cost less to cast.
3/2

Fear of Luposlipaphobia
Enchantment Creature ─ Wolf Nightmare (R)
Menace
When Fear of Luposlipaphobia enters, put a -1/-1 counter on each creature opponents control. If that creature was equipped, put two -1/-1 counters on it instead.
3/3
The fear of being pursused by timber wolves around a kitchen table while wearing socks on a newly waxed floor.

having luposlipaphobia is one thing, but being afraid of it seems a bit much

Fear of Plagiarism

Enchantment Creature - Nightmare (M)
Whenever an opponent casts a spell, you may copy that spell. You may choose new targets for the copy. This ability triggers only once each turn. (A copy of a permanent spell becomes a token.)
Kylo was so scared of other mages copying his ideas, that he started writing in code. His code was the first thing to be copied.
5/5

Fear of Nothing

Enchantment Creature - Nightmare {C}
When Fear of Nothing dies, you may draw a card. If you do, discard a card.
0/0