Defused grenades and "Satan's pizza cutter" were among the 10 strangest things that Transportation Safety Administration agents found when scanning passengers' carry-on luggage during airport security checks last year.

The items listed by TSA spokesman Bob Burns in a clever, funny video include defused hand grenades, "Satan's pizza cutter," a rifle-shaped umbrella, and a lightning bolt-shaped martial arts throwing star, which Burns refers to as the "international symbol for 'I'm single, ladies.'" Travelers inexplicably thought they could take the items on a plane.

Incidents with actual guns are not that rare, either. TSA reports that 73 firearms, 62 of which were loaded and 26 of which had a round chambered, were discovered in carry-on bags in airports around the nation in just the week leading up to Christmas. The agency doesn't say how many of those 73 cases involved a passenger trying to bring in multiple guns.

TSA notes that passengers often attempt to bring onboard "inert" — that is, empty and/or defused — explosive items such as grenades or shell casing, presumably thinking that because they cannot explode they're allowed. "We don’t know grenades or other types of ordnance are inert until our explosives professionals take a closer look, and that takes time and slows down the line. It can even lead to a complete shutdown and evacuation," the agency said.