This was mentioned in the Mk.ii/PS3 thread, but I think it's an interesting enough fact that a lot of people in the west weren't aware of since Snatcher wasn't as much of a thing in the west.
It's first appearance was on the PC-88 game Snatcher made by Hideo Kojima, 20 years before he became a cell powered recon tool for Old Snake.
(the first bit of red text reads "Metal Gear Mk_2", this wasn't just a case of sharing similar designs. Kojima specifically brought it back as an easter egg in MGS4)