Character design is hard..super hard.
My drawing style is not so cartoony by default so I always have a hard time coming up with a simple and strong character. It takes lots of experimentation before I actually start to like what I draw...in many cases the evolution  starts with an accidental shape that I didn't intend to draw...and I take it from there..
This is how I got to the point where I am with the main character. It took me about three weeks...working about 4~5 hours a week at tops..

I started with a design I'm farmiliar with.. some what square facial shape that I got used to doing some freelance work last year.. after drawing similar figures couple of tries, I realized I didn't like the ponty jaw shape so I drastically flattened the chin resulting in more ape like mouth shape.  I started to get vague idea of what I'm going for by the pose study on the far right.

One on the far left was the first design I was kinda happy with.

I kept on experimenting with the how far the mouth and forehead would stick out.

also with how smooth I want the jaw to be connected to the neck.

I still had a hard time making him somewhat slick while keeping the cave man like features.

After about two weeks, I got to the last drawing. For now this one is the defining model that I go back to when I start messing  up the proportions of facial features.

At one point,  I heard somebody saying that Russel Brand looks like a gay caveman,so I kinda deviated from the designs that I had and tried to figure out what made him caveman like.. well it didn't really work...

These are some of the failed experiments...I kinda liked the thick eyebrows and guyliner and that's pretty much only thing survived from these sketches.

Well.. that's all for today, I'll post something similar for the dad tomorrow  and have more new character studies!