There are many references to animals in Othello and they are almost exclusively crude or derogatory. In the first scene Iago intentionally plays upon Brabantio’s prejudice against Othello when he calls him a “barbary horse” and conjures up the graphic image of an “old black ram” “tupping” Brabantio’s “white ewe.” Throughout the play Iago uses animal imagery to emphasise the lack of regard he has for one person or another, particularly with regard to women. He refers to Desdemona as a “guinea hen” and says that if he were to ever feel anything as deeply for her as Roderigo does he would “change my humanity with a baboon” (Act 1, Scene 3). Here he shamelessly insults both Roderigo and Desdemona straight to Roderigo’s face. It is clear that for Iago animals are lowly, unsophisticated, stupid creatures and not deserving of even the slightest respect. Insulting those around him through comparison to the base desires and behaviour of animals is part of an attempt by Iago to find any way to elevate his status or assert some dominance over the other characters in the play.
Iago has a particularly graphic turn of phrase, and at times it is blatantly violent. The way he talks about things that are ordinarily associated with softness or innocence gives a great insight into his character. When he suggests that rather than wallow in self pity Roderigo should “drown cats and blind puppies” it is obviously an intentionally subversive image that often elicits a kind of shocked laugh from audiences, gobsmacked at the inhumanity of what they are hearing.