I remember doing this years ago on DeviantArt, but I figured it's a really good way for comic creators to go in depth about our characters; and also we get to promote our comics AND share some love for others too!
It's pretty easy: right-click / save the image below (a transparent PNG), and open it on your favourite drawing software.
If you are a traditional artist, just draw on your favourite medium, scan it and then photoshop it on the image below.
I'll upload mine soon to get the ball rolling! If you do yours before mine, you win +1000 points.