1.Combine flour, sugar, cocoa and salt; set aside. Combine butter and vanilla in large bowl. Beat with electric mixer at medium-low speed until fluffy. Gradually beat in flour mixture until well combined. Cover and chill dough at least 30 minutes before rolling.
2.Preheat oven to 350°F. Form dough into 1-1/2-inch balls. Roll balls gently to form 5- to 6-inch logs about 1/2 inch thick. Shape into worms 2 inches apart on ungreased cookie sheets.
3.Bake 12 minutes or until set. Let stand on cookie sheets until cooled completely. Create eyes and stripes with white frosting.