The basic form is attributed to Kees van Moorsel (died 1981) since 1941 owner of the Vier Paddestoelen pottery (production until 1951) and from 1953 on owner of Pottery 't Kalkoentje in Remmerden, near Rhenen. The originals have the hallmark "KvM", I have one of them since january 2016.
The others in my collection are (I assume) pigs produced by Pottery 't Kalkoentje between 1953-1976, with no brand KvM, one is hallmarked Rhemus. Length ± 15 cm. Retro Art Deco decor. Substrate: matt glaze, gray marl.
The first of these funny piggy banks I found in the 70’s at the former department store Vroom and Dreesman in Zwolle. The red one with black spots is made by Pottery Frodo. Frits Rood was a ceramist in Alkmaar (famous from the cheese carriers) and used the name Frodo. His work was signed with a sticker, but (as usual) these stickers were removed. So identifying for sure is not possible anymore. The other examples of these cute piggy banks are imitations or also made by Frodo. Size: about 11 cm. Dated: 60s and 70s.