Catullus 23 describes a Furius so dry and poverty-stricken that he defecates less than ten times a year. Pretending to admire the curious economy of this constitution, Catullus declines Furius’ request for a loan, saying that he and his dry, wooden family are sufficiently ‘blessed’. In the following poem, he discourages Juventius from accepting the attentions of this impoverished fellow. At Sat. 2.5.39–41 Horace describes a Furius who, swollen with rich tripe, bespatters the wintry Alps with ‘snow’. This is contrasted, in the previous lines, with the dry heat of Canicula (the Dog-Star) which causes speechless statues to split. Scholars have identified this Furius with the turgidus Alpinus at Sat. 1.10.36–37 whose bombastic epic style Horace rejects. These references and evidence from Quintilian (Inst. 8.6.17) encouraged scholiasts to link the Furius of Horace, Sat. 2.5 with the poet Furius Bibaculus of Cremona. Scholars subsequently identified Catullus’ Furius with the same. If these Furii are the same people, why are they described in such contrasting terms? This article compares Catullus’ Furius and Horace’s Furius in terms of the ancient theory of the humours and in relation to stylistic theory. It argues that Horace deliberately alludes to Catullus and that a sophisticated network of metaphors links their Furii.