Rhubarb the Grouch is the Grouch of Christmas Past in the 2006 special A Sesame Street Christmas Carol. Rhubarb is considered "grouch royalty" for his accomplishments in London, 1843 (the year A Christmas Carol was published). Rhubarb is clad in chains, reminiscent of Jacob Marley. However, Rhubarb is neither repentant nor tortured, and just enjoys his grouchy chat with Oscar. Christmas visitation is only his temp job, in fact, as normally he haunts Her Majesty's wastepaper bin.
He closely resembles Oscar's Uncle Billy in design.