Angry Chimpanzee - Pen Drawing

Hi all, greetings!
Here is my new artwork from my animal series. It's been a while I drew Chimpanzee. I think I should look into drawing them more often. They are always fun to draw - especially those their expressions and fur.

In this one, the focus is on his expressions. I drew an angry looking chimpanzee with stain face. Someone must have provoked him to the level of showing his grievance.

The drawing was done with a blue ballpoint pen on a cardboard paper using scribble and hatching style. You can see my steps below:

Thank you.