The Blue Veil of Death
(M/F compatible) You may unfortunately know the blue screen of death because your computer left you in the lurch someday... But do you know that you can make everybody turn blue by throwing this flash grenade in a public room? It will scare (and annoy!) all of the persons attending if that's your purpose.
To be used with care though, not everybody likes this kind of (out of the blue) humour!
Comes with an extra anguishing -or funny, your pick- and 'out-of-this-world' sound!!!