Euskara is not as rich as Spanish concerning swear words, unfortunately LOL. But here you are some of them, always roughly translated.. You can never learn too much, right?? ;D
Tontolapiko, Kaiku = Dumb, Stupid
Utzi bakean! = Leave me alone!
Pepelerdo, Ergel = Jerk
Kabroi = Bastard
Zoaz pikutara! = Go to hell!
Zoaz popatik hartzera! = F*ck off!