The term originates from a symbol. It is the combined image of a bat, a heart and a skull. The symbol is used by Clandestine Industries and can be seen on clothing and band members of Fall Out Boy. Most noticeably on the bonnet of the car driven by the vampire hunters in 'A Little Less "Sixteen Candles" a Little More "Touch Me"'It is also the name of a film company associated with Pete Wentz of Fall Out Boy, which has produced the DVD 'Release the Bats'
Bat , Heart , Skull = Bartskull