Othello's Appetite
After Iago hatches his plan to destroy Othello, he tells Roderigo that "The food that to him now is as luscious as locusts shall be to him shortly as bitter as coloquintida" (1.3). In this simile, Iago refers to Desdemona as a delicious and tempting food (locusts were considered a delicacy at the time) that will soon be replaced with a bitter and unappetizing plant that will repulse Othello entirely.
Iago's Jealousy
In Act Two, Iago expresses doubt over Othello's honor, suggesting that Othello may have slept with his wife, Emilia. He says, "For that I do suspect the lusty Moor / Hath leaped into my seat. / The thought whereof / Doth, like a poisonous mineral, gnaw my inwards" (2.1). In this simile, Iago compares the thought of Emilia's supposed infidelity to a poison that eats away at him from the inside.
Reputation
Part of Iago's manipulation of Othello relies on his convincing Othello that the protection of Othello's reputation is of paramount importance. In Act Three, Iago says to Othello, "Good name in man and woman, dear my lord, / Is the immediate jewel of their souls" (3.3). Here, Iago uses a metaphor to compare one's good reputation to a precious gem that becomes invaluable to the the owner.
Jealousy
In perhaps the most famous metaphor in the play, Iago cautions Othello against his feelings of jealousy, saying, "Oh, beware, my lord, of jealousy! / It is the green-eyed monster which doth mock / The meat it feeds on" (3.3). In this metaphor, Iago compares jealousy to a monster that both destroys its victims and taunts them while it does so. The central irony of this quotation is that Iago is the character stoking Othello's jealousy throughout the play.
Desdemona's Purity
In the final act of the play, Othello pauses briefly and evaluates his plan to murder Desdemona. He feels uneasy by the notion of killing her, saying, "Yet I’ll not shed her blood, / Nor scar that whiter skin of hers than snow / And smooth as monumental alabaster" (5.2). Here, Othello uses a simile to compare Desdemona's white skin to snow and alabaster, a white mineral. He briefly debates whether he wants to "stain" her skin with the redness of blood, showcasing his internal battle between his love for his wife and his raging jealousy.
