According Museum:
A close follower (perhaps a student) of the Northern painter Hieronymus Bosch executed this sheet. Four of the grotesques depicted are copies from a drawing attributed to Bosch, now in Berlin. Neither this nor the Berlin drawing is related to a known painting, suggesting that the student used Bosch’s drawing as a model, a common workshop practice. Bosch’s works were filled with devilish creatures, highlighting his theme of the conflict between good and evil in the human soul.

Signature bottom right: Jeron. Bos.  See also drawings of monsters in Oxford.