The Caproni Ca.133 was designed as a three-engine colonial bomber and transport and was first flown in 1935. Many hundreds were built and when Italy entered the war in 1940 the Ca.133 equipped 14 Squadriglie di Bombardimento Terresti (bomber squadrons), nearly all in East or North Africa. In the 1930s these versatile machines gave exellent service, but by 1940 they were totally outclassed.
Their crews called them Vacca (cow) or Caprona (she-goat), which was a play on the name of the manufacturer.
Source:
Info: Fighting Aircraft of World War II - Salamander Books
Profile: Wings Palette - http://wp.scn.ru/en/