Someone who runs themself into the ground at work in the (sometimes misguided) grand persuit of a little extra credit on their flexi-time record. These people usually arrive in the office at 0700 and leave at 1800, normally sporting a pale and nervous disposition
Office Worker 1: "Why are you working so late?"
Office Worker 2: "To get some credit on my flexi so I can leave early on Friday"
Office Working 1: "You flexi junkie!!"