Television’s longest-running children’s animated series, “Arthur,” has joined the ranks of the children’s characters that are now part of Percy3D’s customizable party invitation site, PercyVites.

Under a new agreement with the show’s producers, WGBH Boston and Marc Brown, Arthur branding will now available in the PercyVite line of digital party products, which allows kids to integrate pictures and party details into clips from their favorite TV series.