In 1935 Hildo Krop designed by order of the paper/magazine De Groene Amsterdammer, 'De Groene in Steen'. This frog was given as a bonus for the introduction of new subscribers for the newspaper/magazine. It is unknown how many of these figures were produced but it is certain that Krop made one of them himself while the rest were produced by the ceramic factory Zuid-Holland, Gouda

cf. E.J. Lagerwey-Polak, Hildo Krop, 1992, p. 126, no. V104, for a catalogue entry of De Groene in Steen