A plaque in Dark Monk's temple describes the Francos as so:
|"Franco representative. The Francos live on the island of the Francos, (what a surprise!), which is enshrouded by the gas swarming with monsters. The Francos refine the gems extracted in the under-gas, and turn them into gazogem, usable by all the vehicles of Zeelich."|
- - A plaque at Dark Monk's temple
As can be seen, the refining of gazogem from gems in the gazogem refinery provides a main income source for the Francos. This is also mentioned in their description in the official Little Big Adventure 2 website:
|"A sausage-like race (with all due respects) living on an island which is particularly vulnerable to gas monsters. They control GazoGem production in their refinery, a fuel extracted from the gems mined in the sub-gas. They are also used as soldiers, policemen, guards, and paratroopers in the Emperor's army. They are first-rankers in all battles, raids and all other forms of butchery!"|
During his adventures in Zeelich, Twinsen mainly finds Francos in Francos Island. At that time, most of them are searching for the lost Francos Fragment. There are also quite a lot of Francos in Otringal and the Island of the Wannies, mainly serving as guards and policemen. During the Emperor's invasion of the Island of the Mosquibees, the Francos are serving as parachuters. A few Franco guards also come to Twinsun with the Esmers.
"Franco" is perhaps a pun on "Frankfurt", the city famous for its sausage industry.