Don Frye

But there has to be a disclaimer: Many mma fighters (past and present) have used steroids. Some guys have been caught (like Josh Barnett) who look like the last person you would suspect of using. First, just like in bodybuilding, genetics obviously play a huge role in how you will look. Second, different guys were using different compounds and different dosages. Lastly, some guys actually enjoyed lifted weights besides doing mma training.
While we are pointing out which guys looked the most jacked, many more have used steroids/peds, and have gone under the radar over the years.
Think Rafael Palmeiro (baseball) compared to Mark McGwire as a good example. Both used.

