fourth-cousin-8X-removed

Fourth-cousin-eight-times-removed (4C8R).

My fourth-cousin-8X-removed is a good person.

fourth-dimensional vampire

A fourth-dimensional vampire is someone who lives in a different timeline and only seeks to further their agenda, often times only appearing to vibe check unsuspecting people engaged in a different activity.

Derek:"Dam I can't believe Steven just dropped by to laugh at me playing cards at the local casino."
Josh: "Doesn't that dude have gremlins now? I haven't seen him since we graduated highschool 10 years back."
Derek:" Yea he hasn't changed much, he really is a fourth-dimensional vampire."

Fourth Wall Fall Wave

When a cartoon character realizes they are about to fall a great distance. But before they begin to fall, they look directly at the screen and wave goodbye to the viewer(s).

Wile E. Coyote is the undisputed master of the Fourth Wall Fall Wave.