From Muppet Wiki

A young version of Rowlf from the Muppet Kids books and video games.

Rowlf is a laid-back pup. He wears blue jeans and a sweater. Rowlf is a talented piano player, and also good at organizing and leading. In Piggy for President, he presides over the group's club meetings and organizes elections.

While Baby Rowlf was a main Muppet Babies cast member, Rowlf plays a minor role in Muppet Kids books. One of his few major appearance is in Piggy Gets the Jitters, where he helps Piggy overcome her fear of public speaking; his other book appearances are minor background roles.