Claudian wrote In Eutropium (Against Eutropius) to denounce the prominent eunuch by that name. Eutropius was a Roman consul in the late fourth century CE and Claudian acknowledges him as the third founder of the city after Byzas and Constantine (2.83), but that doesn't stop Claudian from making pejorative references to eunuchs as "half men" (1.171, 2.22). Jacqueline Long writes, “Any androcentric culture would find emasculation a natural invective tactic.” (Long, p. 122) Claudian depicts Eutropius as greedy, a stereotype of eunuchs that may have formed from the assumption of the displacement of lust for sex toward lust for money. A spin on the meaning of a eunuch’s childlessness — namely, that it leaves him emotionally stunted and not learning how to bond or serve others (rather than affording an opportunity for displacement of the tendency to bond and serve) — appears in Claudian’s words: “a eunuch is moved by no devotion, nor does he fear for family and children,” (1.83-88, as quoted by Long, p. 135).
Much of the criticism is not just abstract, but sensory:
“The figure of the eunuch makes an irreconcilable antithesis with all the honors Eutropius achieves. Creating a vivid sensory impression that will remain in the audience’s mind is the imagery’s most important task. An example of its effect, with supporting details further elaborated, is given by the contrast of the slavish, effeminate, shameless, sagging, filthy, whining, bibulous eunuch’s impersonation of a triumphator.” (Long, p. 121)
Claudian asked sarcastically, "Have we ever seen a temple built or altars raised to a eunuch god?" Of course we have — the Egyptian god Osiris. This point of Claudian's does not stand up to scrutiny.
Furthermore, within Claudian's poem, Cybele watches the self-mutilating Curetes dance. See also Luc. 1.559-63; after this section, there is mention of Bellona and Cybele’s self-mutilating priests. (Long, p. 110)
In "Don Juan: Dedication," George Gordon Lord Byron (1788-1824) used the term "intellectual eunuch" to complete the metaphor of the adoration of a sultan in Stanza XI. In Stanza XV, the words "emasculated" and "Eutropius" appear, associating castration with servitude.
Jacqueline Long. Claudian's In Eutropium: Or, How, When, and Why to Slander a Eunuch. Chapel Hill: University of North Carolina Press, 1996.