Bowser Jr.

This is the son of Bowser and is not to be confused with Baby Bowser. He looks just like Bowser except younger and he constantly wears a bib with fangs drawn on it perhaps to look more intimidating. His first appearence was in Super Mario Sunshine where he tried to frame Mario of crimes he didn't commit. This plot actually succeeded. He has been seen in other Mario games since then. He even appeared as a final boss along with his dad in the New Super Mario Bros. game for the DS.