Who is Roderigo? What is he like?

Roderigo

Lusts after Desdemona, which Iago is of course aware of. Iago uses him to ruin Cassio's reputation, and in his other schemes. Iago promises Roderigo that he shall have Desdemona's love in return for his help; Roderigo actually receives nothing but a disgraced death. He is pretty pathetic!

Roderigo is Iago's pawn. He is lovesick for Desdamona, and he is used to spark her husband's jealousy. His love for Desdamona makes him easily manipulated and used.