Who is this guy? This guy, as you call him, is King Bowser Koopa, better known as Bowser. He is a character from the Super Mario series and is the main antagonist of the aforementioned series. Most of the time, Bowser is found trying to capture the monarch of the Mushroom Kingdom, Princess Peach, with the aid of his so-called army to extend his power and to be known as the most powerful being that the Marioverse has ever seen. He also has an obvious crush on the lady. On some rare occasions, he will team up with his arch-nemesis, Mario, to stop the world from any kind of destruction.
That's all good, but what is he like? Being the antagonist of the series, Bowser is seen with many bad traits. He is very self-centered and only wants power; In other words, he thinks he is the navel of the world. He doesn't really care about anyone else but his son, Bowser Jr, and his high ranked lieutenants, namely the Koopalings. He is so full of himself that he would only help Mario to save the world so he could have a world to conquer. He is also portrayed as being a comical villain, throwing random statements and calling literally everyone silly names. Bowser does have a soft spot, but only for Princess Peach.