My Parasprite card is basically Spawnwrithe, but a 1/1 flyer instead of a 2/2 trampler.

@FanOfMostEverything  
I didn’t even think about tokens. Whups.
 
The problem is that if I make it just noncreature permanents, these things will start devouring lands at a ridiculous rate. And if I make it noncreature nonland permanents, it loses a lot of its effectiveness.
 
That said, any self-respecting burn deck would barbecue these guys before they became a problem.

@The Hittite  
Actually, as written, you could kill CMC 0 permanents just by paying one green mana. No Parasprites were tapped, so X equals 0.  
All the more reason to add “noncreature” if it can annihilate tokens like that as is…

All fair points.
 
@FanOfMostEverything  
The program I’m using to make these converted it into a mana symbol automatically and I’m having trouble getting rid of it. Very good point about targeting creatures though.
 
@TheOneTrueZephin  
I mostly just threw that in so you could target things with a CMC of 0.

@DutchGentleman  
Ooh, that’s a good point. The phrase in the cost should be “Tap X untapped creatures you control named Parasprite.”

Or the owner of the destroyed permanent gets the parasprites, perhaps?

I like this card, but I agree with the no creatures statement of fanofmosteverything.
 
But I would make it “equal to “X” instead of “X” or less”. it would put a slight limitation on their ability to proliferate while making it slightly more accurate to source material.

You may want to add “noncreature” to the target. Green doesn’t usually go for creature kill that doesn’t involve combat or fighting. That, or make this adorable little consumer of worlds cost BG. Also, when referring to converted mana costs, do not use a mana symbol.
 
Oh, and on the off-chance anyone cares, here’s my take on Parasprites:
 
Parasprite UU  
Creature — Pest  
Flying  
At the beginning of your upkeep, put a token that’s a copy of Parasprite onto the battlefield.  
Tap two untapped Pests you control: Tap target land.  
0/1