Peter Piekos (1918-2000) was a voice actor on Sesamstraat, the Dutch co-production of Sesame Street. He was the original voice actor for Cookie Monster, Herry Monster, and the Big Bad Wolf.

He also occasionally performed the voices of Herbert Birdsfoot, Sherlock Hemlock, and Tough Eddie, as well as many of the narrators; his regular voice sounded like an old fashioned radio announcer. During the late 1980s, Hero Muller took over both Herry and Cookie.

Unlike the original English-speaking Cookie Monster, the Dutch "Koekiemonster" uses correct grammar.