lol there's a funny story to this XD my friend put a face lik this on a orange cause she hates them is the short version :D but yeah.
Step 1:
Outline a circle tyhen go back and darken it.
Step2:
With transparent orange go through and color it a till ur 1 away from the darkest.
Step3:
go and add a shadow with ur last darkening of transparent orange:
Step4:
add the grooves and face to the orange.
Step5:
Color the teeth in with transparent white and add red to the mouth and a bit of red on the teeth.
Step6:
add a dark arura :D