Jabba the Hutt comes to mind.

nefarious (ne·far·i·ous): / ni FAIR ee uhs /
adjective

(1) extremely wicked; flagrantly villainous; utterly immoral; impiously evil

[From Latin nefarius meaning “wicked, vile,” from nefas meaning “crime against divine law, sin,” from ne- (“not”) + fas (“right, divine law”).]

Usage: One would like to consider Dubya an incompetent boob, yet that would do little to explain his nefarious plots and machinations.