Explain what the following speech illustrates about Iago's character.

IAGO: I have rubb’d this young quat almost to the sense,
And he grows angry. Now, whether he kill Cassio,
Or Cassio him, or each do kill the other,
Every way makes my gain. Live Roderigo,
He calls me to a restitution large
Of gold and jewels that I bobb’d from him,
As gifts to Desdemona;
It must not be. If Cassio do remain,
He hath a daily beauty in his life
That makes me ugly; and besides, the Moor
May unfold me to him; there stand I in much peril:
No, he must die. But so: I hear him coming.