The white pony bringing up the rear is probably Augereau, a favourite horse that the artist purchased from a Norwich dealer, Drake around 1907. Munnings describes him as 'the most picturesque of white ponies - an artist's ideal. A white horse has been used in many pictures by many artists. Augereau's name may go down to posterity as the last of his disappearing race to pose as a model for a picture'. The dealer had warned Munnings ''e 'on't 'ev nothin' to dew wi' a cart or 'arness, but what a beautiful pony for a picture!'
(A.J. Munnings, An Artist's Life, Suffolk, 1950, p.p.196, 198)

Munnings' other favourite model also came from Drake's, Shrimp, the gypsy boy who looked after Drake's horses. He took a fancy to the 'toff' and made sure that he got to know Munnings at the Saturday markets where he bought horses. Eventually Munnings was invited to spend a week with the Drake family in the hamlet of Aylesham. Shrimp posed for Munnings every day from dawn to dusk, holding or riding Drake's ponies in a country lane for Munnings to paint. It was not long before Munnings realised that he had found the 'best model I ever had' and the beginning of a long and fruitful partnership was born
(See J. Goodman, What a Go! The Life of Alfred Munnings, London, 1988, pp. 84-87)