How about Jonathan Coulton?  Then his song Re: Your Brains could become real.  Then you can have real flesh eating zombies running around.  But that is the night they go to check out what is going on.  The previous night, several programmers are transform into monkeys because of the song, Code Monkey.

The cause is his new Guitar.  Poor Jonathan isn’t even aware it is doing it.

Currently, I'm going for a +3 catch. I had a few ideas before, mostly along the lines of Special Material, common (+2) and Difficult Research (+1).

My take you are going adding too much value (mathematically) for your Catch.  The Difficult to Research would reduce the value of the Catch, not increase.  So, it would become a +1 Catch, not +3.

Also, I wonder how high circles extend up? And do they go down too? Magical circles are commonly placed on ceilings in Supernatural but is that because they are aiming down? Can flying or burrowing demons get caught in a circle?

I interpret them as going high enough to cover what is required in side and deep enough to be below the circle. 
The other answer, is they are the size to fit the plot.

Suggestion: Only the wizard's clothes become invisible.

Oh, that gives me an idea.  Give the companions of the wizards the aspect: EMPEROR’S NEW CLOTHS.

I like the idea that Fallout should make things difficult for the Wizard, failing that, his friends.  I’m sort of looking forwards to a wizard causing fallout for a veil and me passing out notes; “Everyone except you is naked.”

My two cents about the Chupacabra, I think it's more likely that it was a Red feeding on animals without his flesh mask (Maybe a blood slave?). 

That is a possibility.  Personally, I think the Chupacabra is an evolution branch of the Red Court Vamp tree.    Like how tree monkeys are a branch of the Homo Saipan tree.

Chupacabra

High Concept: Blood sucking hunter
Other:  Catch me if you can

Skills:
Great:  Stealth, Athletics, Intimidation
Good:  Fists, Alertness, Endurance
Fair:  Discipline, Survival
Average:  Conviction, Presence


Powers:
Echoes of the Beast –1
Incite Emotion, At Range –2
Inhuman Speed –2

Stunts:
No Pain, No Gain
Tough Stuff
Swift and Silent


Stress:
Mental: OOO
Physical: OOOO
Social: OOO

Refresh Spent: -8

When the Chupacabra screeches the its eyes glow an red and all in hearing suffer nausea (Incite Emotion).  The attack is Intimidation based defended with Discipline.  Those that fail, suffer a sticky aspect, Nauseush.


Note:  This is my first creation with Fate/Dresden.  Anything wrong?

Edit:  fixed Physical stress track.  Added Other aspect, Catch me if you can.

If I have a situation where I compel corruption part of the city aspect “Corruption and Decadence”  to limit the groups actions, who gets that Fate Point.  Everyone?  Which is fine by me.