Red Faction Guerilla Glitch

Red Faction Guerilla is a fun little sandbox/3rd person war game to pick up on the cheap. You play a Martian Colonist who fights an oppressive government, mostly by blowing up/knocking down buildings or making small raids from various outposts. The enemy forces have various patrols about, including hovercraft-fighters that you can shoot down.

This one seems to have spawned partially inside a mountainside, mostly invisible (except for the engine plumes) and completely unkillable, primarily due to its lack of existence.

 You could hear the not-engine going full-bore.

 A cunning defensive strategy, but not exactly useful unless the plan is to win via global warming.

 This is particularly weird, because the game does allow for these hover-fighters to crash into mountains if they take a bad flight path.