The actual Christoper Walken has some of the same features as your drawing.
That man in your drawing has a giant fore-head.
The actual Christoper Walken does have a large fore-head but not to the same degree.
You exaggerated his forehead by a lot.
Christopher walken has very squinty eyes and I love how you included laugh lines in his face.
The pose is actually kinda boring to be honest.
I would like to see you try doing more dynamic poses with this drawing.
I personally struggle with working out the poses in my own pictures.
Draw a stick man version of the pose first if it helps.
Build onto the stick man by adding more details on top of it.
I seen other animators advise others to draw the forms before adding details.
Just do whatever works for you.
A background could liven up the picture a bit.
Perhaps walken is posing for his driver license photo.
He could be standing on a launching pad before his rocket pack activates.
Use your imagination to create interesting poses with your drawings.
I will have to do the same and take my own advice.
Do another Christoper walken drawing but with a more dynamic pose.
As always; I look forward to your new work.