Biographies on professional wrestlers and mixed martial artists can be very tricky undertakings due to individuals trying to make themselves look better or being less-than-honest in order to cover for someone else. Throw in a life filled with illegal drugs, illicit affairs and shady business deals, and it’s remarkable that Jonathan Snowden’s “ Shamrock: The World’s Most Dangerous Man” paints as complete a picture as it does. It’s a fantastic look into the triumphs and failures of Ken Shamrock, who has led a full life as an MMA pioneer, pro wrestler and father.