wheel horse
noun: 1. Someone responsible and diligent, especially one who bears the biggest share of burden in a group. 2. A horse harnessed closest to the front wheel(s) of a carriage.
The Science of Web Design & Search Marketing
noun: 1. Someone responsible and diligent, especially one who bears the biggest share of burden in a group. 2. A horse harnessed closest to the front wheel(s) of a carriage.