Zippy the Monkey ('Zip the Monkey', or 'Zip the Chimp') is a stuffed rubber faced doll chimpanzee doll that was introduced in the 1950s on the TV show Howdy Doody. The chimp doll was produced in the 1950s, with reissues in the 1960s and 1970s by a number of toy companies but most notably by Rushton.
Zippy has a shirt on with Zip on the front and was fashioned after Zippy from the Howdy Doody show. Because Rushton made the doll a little pricey, several toy companies made monkey dolls that looked very similar but cheaper.
See also: Howdy Doody dolls.
What's it worth? Take a look at this Zippy Monkey price guide: sold listings for a value indication.