This cog structurally resembles a bag, as it has a big, round frame and an oddly-shaped head more than anything else, and looks like the end of a tightly-filled bag that has been tied shut. Its face also appears to be at the top of its head and its neck is probably a knot to secure the item inside which is probably money.
The Money Bags' weakness is the Safe, since being crushed by something that holds money is painful.
This is the only cog that appears in all of the Cashbot Headquarters hotspots. This includes the trainyard, the mints, and the vault.