Thought it might be cool to share the full process on this guy - Oscar. NOTE - this work is about 5 yrs old now. It took about a month, give or take. Many iterations, lots of back & forths and it's pretty much all in this post. Final version on top, the very first pass on the bottom and everything in between. I didn't edit anything, it's pretty much how I have it in my folders. A sort of a real time process insight.
In Gears 4 they gave him a comical voice with a heavy accent, which I totally didn't picture while designing him. Thankfully they rectified that in Gears 5.