Travis Barker -- Down with Peter Griffin Now, Esé

Travis Barker is doing a new mash up with none other than Peter Griffin ... after scoring an apparel deal with "Family Guy."

Travis' clothing line ... Famous Stars and Straps will be selling gear with artwork featuring characters from Seth MacFarlane's hit show. Sources connected to Travis tell us he got his favorite tattoo artist to draw up the first design ... with a little East L.A. flavor.

We're told Trav and co. plan to crank out all kinds of themes for the line.