Lets start with a simple guideline. draw some simple circles for the head,body and hands,with some lines for the limbs.
Lets add some detail now. start with the eyes and add some details to the shoes and gloves.
OK. Now draw some simple ovals for the pupils and draw some fingers. Draw the oval shaped thing on his body and the muzzle part on his head.
Draw the three spikes on the back of his head and two to tthe back of his body,add some flesh to the legs a smiling mouth and a simple triangular ear. Also draw a small oval inside his pupil to show some eyeshine.
Draw some final detail to the shoes,like the straps,add the other ear and put in the final three fingers. Finish off with the arms, gloves and eyes
You've made it to the end with a finished sonic. Just add some colour if you want and enjoy your picture!