When a string of unexpected and potentially annoying or crappy events occur, or when annoying or crappy people/animals/objects begin to appear in rapid succession without prior notice.
William Shatner's musical career has been pooping out the woodwork recently.
12 step recovery jargon referring to someone new who talks about how great life is, now that they'resober. Usually meaning that the person is out of touch with reality.
The new guy seems pretty happy for a dude who has no job, no money and no family. He must be on a pink cloud.