The process for taking a blueprint of an object in a 2D state and making it appear to be in perspective, is called Orthographic Projection. If you've never had to do this before, it's a pretty complex process to wrap your brain around. Rest assured, if I can figure it out, ANYBODY can.
 
You start by creating your blueprints of whatever it is you want to place in perspective. You need to make sure you have at least two perpendicular views. In this case, I used a side view and a top view.

Then take those blueprints and place them in any program that provides, at least minimal, perspective tools. I used Illustrator. I use it every day so it was a no-brainer for me. You can do this all by hand as well. You have to have a decent grasp of geometry in order to do so. I've done it. It's a TON of work. If you have a program that will handle the geometry for you, it's going to keep you from balding prematurely. 
 
If you place your blueprints in the front corner of the grid, as I have here, it acts essentialy as a "wide-angle" lens. It will distort your final result. The further back in the grid you go, the more "normal" your persective will be. I started with a crazy little creature so I left it in the front for effect.

I've hidden the grid from this view for ease of viewing. Once you have your blueprints placed where you want them in the perspective grid, then you start plotting points of reference so your object in perspective is accurate. It's a lot like how astronomers plot stars in relation to geographic locations. You just pick a point on the side view and find where that same point is in the top view then draw your lines in perspective to where those two points meet. That spot will be one of a billion reference points you'll use to draw your object. 

As you go along, you'll want to remove non-essential perspective lines so your image doesn't get too cluttered. Once you've plotted everything and removed any unnecessary lines, clean up your drawing by fine-tuning curves and line-placement.  

Now you're ready to take your earthworm into battle!
 
It's a pretty time-intensive process, but it's a great way to take your idea from concept to final product. In the professional world, it definitely gives your art an edge that will get you more notice and more jobs.