Klatter is the sixth collaborative release between the Japanese experimental doom band Boris and Japanese noise musician Merzbow. The album features re-recorded versions of "Akuma no Uta" and "Naki Kyoku" from Akuma no Uta, and a cover of "Jane-Session" by the German progressive rock group Jane.It was originally planned for release on Troubleman Unlimited in 2007 under the unconfirmed title Mellow Peak, but for unknown reasons it did not happen.