One who spends all of his/her time playing halo until they get so good that they go pro and get sponsored, thus getting paid to play halo. Your xbox live gamertag becomes are regular word in halo talk.

When you eat dirt for the first time and leave your family to build a shack in the woods

One who spends all of his/her time playing halo until they reek like old fecal cheese. They get sponsored by their mother to take a shower and possibly open a window.

Their xbox live gamertag remains cliche and irrelevant, although they become convinced that xXXsNiPER420Xxx is a household name. They are unaware that symbols around their names, such as x's and 0's, are indicative of the thick acne on their faces.

They often employ spreadsheeting tactics by playing the same map hundreds of times each day until all scenarios are worked out. When confronted with a new scenario or situation, they flounder, then rage, killing their teammates to take the power weapons for themselves.

Halo pros frequently drop when the game begins under any circumstance that is not advantageous.