Merchandising
Around the time of Sesame Street 's 35th anniversary, licensors finally started to notice and recall the characters. In mid-to-late 2003, Hot Topic led the way with the first-known official Yip Yip merchandising, a "vintage"-look T-shirt with two Martians. This was followed in the fall of 2004 with Gund bean-bag toys. Light switch plates, action figures (by Palisades Toys), and stuffed toys followed. The 2006 Sesame Street calendar features the Yip Yips for November, and they make an appearance on the front cover.
The only real acknowledgement of the characters previous to 2003 was their mention in the 30th anniversary book Sesame Street Unpaved.
Read more about this topic: Yip Yips