"Rowlf is a droll and dogged piano player who enjoys tickling the ivories as much as he loves tickling the funny bone of his audience. Whether playing Poochini or cracking a joke that's older than a bone, Rowlf is one of a kind. A graduate of the Ruff Barker Obedience & Music School, he majored in piano playing, punning, and advanced fetching."
Every Muppet has different things that they like. For every unique object that they like that's placed on the stage, the Muppets's happiness will increase by one (in other words, placing two of the same liked item will still only increase happiness by one ).