The god of love, and son of Venus. According to fable he wets with blood the grindstone on which he sharpens his arrows.
Ferus et Cupido Semper ardentes acuens sagittas.'
Horace: 2 Odes, viii. 14, 15.
The best statues of this little god are “Cupid Sleeping,” in Albano (Rome); “Cupid playing with a Swan,” in the Capitol: “Cupid mounted on a Tiger,” (Negroni); and “Cupid stringing his Bow,” in the Louvre (Paris). Raphael's painting of Cupid is in the Farnesina (Rome).
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894
More on Cupid from Infoplease: