Courtesy of Rikk. Octaman (1971, writ./dir. Harry Essex) has 4 arms, 3 eyes, and sees 5 of everything. That kinda works out to 8, if you count his eyes plus his field of vision. But it's hard to argue for him really being eight-based. It does argue for his general state of confusion and inability to figure out what his prey is doing or react constructively in a high-pressure situation.