According website Christies:

One of the most innovative and original painters of his time, Hieronymous Bosch’s work had a significant and lasting impact on the visual arts throughout the sixteenth century. Through their intensely imagined scenes of demonic temptation and tumult, the master’s work pioneered a significant new visual and iconographic language, which was quickly taken up by painters working across the Netherlands in the decades after his death. The Temptation of Saint Anthony was a popular Boschian subject and at least six treatments of the subject by the master, or his workshop, survive: the left wing of the Hermit Saints Triptych (c. 1495-1505; Venice, Gallerie dell’Accademia); a fragmentary panel of c. 1500-1510 (Kansas City, Nelson-Atkins Museum of Art); the famed Triptych of the Temptation of Saint Anthony (c. 1500-1510; Lisbon, Museu Nacional de Arte Antigua); the left wing of the Job Triptych (c.. 1510-1520; Bruges, Groeningemuseum, long-term loan from Hoeke, Sint-Jacob-de-Meerderekerk); and a small Temptation, with a debated attribution (Madrid, Museo Nacional del Prado).
The present panel appears to have been painted in Antwerp, where Bosch’s influence was felt very strongly, in part due to the circulation of prints after his work. While evidently using Boschian ideas and figures, the picture bears a number of stylistic affinities with Antwerp ‘Mannerism’, a style which predominated in paintings produced in the city during the early-sixteenth century. The figures of Saint Anthony and the teeming demons and devils which populate the exaggerated rocky peaks of the land and townscape beyond are reminiscent of the work of Jan Wellens de Cock, who registered at the Antwerp Guild of St. Luke in 1506. The painter is documented working in Antwerp undertaking decorative works in the city’s cathedral in the succeeding two years and later serving as co-dean of the Guild alongside Joos van Cleve. While no signed works by the artist are known to survive, his oeuvre was reconstructed by Friedländer on the basis of a panel depicting Saint Christopher (Private collection), which was copied in an engraving bearing the inscription ‘Pictum/J. Cock’, allowing for a tentative basis around which his opus could be grouped (M.J. Friedländer, Early Netherlandish Painting, Leiden, 1974, XI, p. 36). The painter is associated with a number of scenes of the Temptation of Saint Anthony, including a work highly comparable to the present painting, now in the Legion of Honor, San Francisco (fig. 1). Though the figure of Saint Anthony differs slightly in its treatment, elements like the landscape background, especially the church consumed by a blazing pillar of flame and the jagged, Patinir-esque rock forms, are very similar in each. Interestingly too, the panel has almost the exact same measurements as the present work. The most marked difference between the two works is the figure of the saint’s female tempter, seen at the right of the Legion of Honour picture, born on top of a demonic form and adorned with an exotically gilded headdress and lavishly coloured gown. Her absence in the present picture is striking and unusual. However, on closer inspection it becomes evident that this temptress figure did in fact originally appear in this work, as the outline of her figure can just be made out at the right of the painting, in the dark area over the water, just in front of the gaping mouth of the fish. As in the Legion of Honor picture, she wore an elaborate headdress, still visible above the lacuna where her body should be, and similarly carried a jewelled vessel in her hand, though here her other hand was raised above it, rather than supporting its base. The reasons why the figure was painted out are not clear, though it appears to have been a later intervention, given the difference between the paint surface of the water beside it and that covering the woman.
One of the most unusual aspects of this Temptation is the large severed head above the figure of Saint Anthony. The blood flowing from the wound drips onto the branch of the tree, pooling there before the stream begins to fall downward, where it will eventually hit the open pages of the saint’s prayer book. The size and prominence of the head is striking and suggests that it must have been intended to play a central role in the painting’s iconography. It is possible that the head represents that of Saint John the Baptist, famously martyred by being beheaded at the request of King Herod’s daughter, Salome. Both Saint Anthony Abbot and Saint John’s legends contained key focuses on their resistance to the temptations or actions of alluring, lascivious women: in Saint Anthony’s through the guise of a demonic temptress and for John the Baptist in the form of Salome. The severed head in this painting may be intended as a reference the perils of feminine temptation.