A MitchMarks is a person who is tall/skinny with long arms and legs, caucasion, of italian/sicilian decent, with dark thick curly hair, big bright blue eyes, heavy drinker and cocaine addict, is very funny, good liar, gets in trouble alot, is sexy, and has a giant cock

Short for ultimate bias. Typically used by fangirls and fanboys to describe their favourite celebrity amongst the many that they are fans of.