Resident Evil 6: Playing Mercenaries (co-op), and the host’s connection starting to act up…and causing lag-teleporting. I noticed it early, but thought I could handle with it; clearly I thought wrong. I got overwhelmed in the tunnels, and ran into the central area for some breathing room. Much to my horror, I found a mess-load of nothing but Bloodshots lag-teleporting all about the place.
Not an exact example of it, but Robin’s hallucination of Slade does come to mind:
(There’s a horror film that has a more exact example of this, but the name currently eludes me.)