I wonder if this was part of a series? Little Giant, Medium-sized Giant, Big Giant, Great Big Giant, and so on?
I can't find any reference to "oddograph," except the company, but there is an "odograph" (one D), which is a measuring odometer (of which there are also nautical versions). I wonder if that's what the company originally made before diversifying into chain cutters?
Maybe an oddograph is a machine that measures how odd something/someone is. If they ever tried it on us (pointing around), we'd probably break it.