work like a Trojan

To work very intensely for a long or continuous period of time, especially doing something thankless or menial. The boss had us working like Trojans to get the project ready on time. I worked like a Trojan the entire summer after high school to earn enough cash to buy my first guitar. I've been out here working like a Trojan while you sit inside sipping lemonade. Could you maybe lend me a hand?

Trojan, he is a/works like a/a regular

A determined, energetic individual; hardworking. The term comes from Homer’s description of the Trojans in the Iliad and Virgil’s description in the Aeneid. In both epics they are pictured as brave patriots who work hard for their country. This view was adopted by later writers, such as Samuel Butler, who wrote (Hudibras, 1663), “There they say right, and like true Trojans.”