Fronted by Frank Iero, best known as the rhythm guitarist for My Chemical Romance, Leathermouth is a post-hardcore outfit that got its start in 2007. Iero developed an interest in the band when he heard some of their original demos, but ended up joining the line-up when Leathermouth’s lead singer proved unable to write lyrics. Iero stepped in to assume lyric-writing and vocal duties, providing him with a more directly expressive outlet than My Chemical Romance. Leathermouth signed to Epitaph Records in 2008, and released its debut full-length, XO, in 2009.