thread hog 

A person that likes creating threads on message boards and in groups before others have an opportunity to do so.

"Chris is such a thread hog. He made the Super Bowl thread in our Facebook group two days early so nobody else could."

thread hog by alexg650 January 31, 2014

Tread-hog 

A scrawny lollypop headed girl or woman, who hogs the treadmill at the gym, walking briskly for hours as though it would make any difference to her emaciated figure, thus preventing others using the machine.

"I had to quit gym early because there were too many tread-hogs"

Tread-hog by Diamond Tee April 9, 2009