The cool thing about Rogon is his evolution. You know the wurmple personality evo? Well, Rogon works the same way. At level 25, if he has a high personality, he evolves into Rogastar, which is fight/psychic. If he has low personality, he becomes Rogetta, a fighting/dark type. Rogastar is more on the good side and Rogetta is more on the evil side.
Rogon starts as pure fighting type though.