Only one other example of this very rare form appears to have been published. A cup with a very similar foot bending to form the dragon-head handle in the Harvard University Art Museum Collection is illustrated by T. Fok, Connoisseurship of Rhinoceros Horn Carving in China, Hong Kong, 1999, p. 86, no. 39.
As with rhinoceros horn waterdroppers, an example of which, from the Songzhutang Collection was sold at Christie's Hong Kong, 27 May 2008, lot 1716, the tip of the horn would have been steamed or heated in hot water for hours before being sufficiently pliable to be bent backwards to form the handle. For a more detailed explanation of this laborious process, refer to T. Fok, op. cit., Hong Kong, 1999, p. 29.