The Ratler Brothers are a quartet of rats who sing "Flowers on the Wall" in a 2015 music video posted to the Muppets' official YouTube, Facebook and Twitter accounts. Their name is a play on the Statler Brothers, who originally recorded the song.
They sing over Beaker's after-work activities and are eventually blown off the screen when Beaker inadvertently causes an explosion in his apartment.
A vinyl record by The Ratler Brothers decorates a wall in the PizzeRizzo restaurant in Disney's Hollywood Studios. In addition to "Flowers on the Wall", the record also features "We Got Paid in Trash", "More Than a Hole in the Wall", and "Sewer and Sewer".