The drawing is a study for some of the marine creatures modelled in stucco, that decorate the frames of the octagonal coffers in the ceiling of the Sala Regia of the Vatican, adjoining the Sistine Chapel. Commissioned by Pope Paul III, Antonio da Sangallo designed and supervised the construction of this chamber during the late 1530s, whereafter Perino was employed to design the decorations -- the stuccoes, frescoes and stained glass windows. Monthly payments to Perino were made from January 1542, and the vault was completed by June 1545, when work began on the stucco frieze of the cornice. The decorations were incomplete on Perino's death in October 1547, when Daniele da Volterra took over the commission; following the death of Paul III in 1549 the work came to a halt, and was not completed until 1573, under Gregory XIII (see B. Davidson, ‘The decoration of the Sala Regia under Pope Paul III’, Art Bulletin, 1976, pp. 395-423).

The drawing is en suite with another vigorous pen study in the Uffizi (inv. 1596-E), of a triton, on the same scale and with the left edge similarly badly creased, and some of the contours pricked for transfer. At Christ Church is a larger drawing of a confronted pair of tritons, much more carefully drawn with wash added to show the desired relief of the figures (Byam Shaw 481). The Christ Church drawing is close in scale to the stuccoes themselves, but none of the stuccoes is identical and none corresponds exactly with a drawing. It is likely that Perino's drawings served as a samples upon which the experienced stuccoists could improvise, rather than patterns to be followed precisely.

There are also numerous copies of the Christ Church drawing, including examples in the British Museum (Pouncey and Gere 192, and 1946,0713.1272), Munich (inv. 2544), the Uffizi (inv. 1651-O), the Louvre (inv. 10451), and Düsseldorf (inv. F.P.160, perhaps by Taddeo Zuccaro).

Inscribed upper centre, in pen and ink: di pirino del uago.