(Ὀλθακός), a chief of the Scythian tribe of the Dandarians, who served in the arny of Mithridates the Great, and enjoyed a high place in the favour of that prince, but subsequently deserted to the Romans. This was, however, according to Plutarch, a mere feint, for the purpose of obtatiinng access to Lucullus, and thus effecting his assassination; but being accidentally foiled in this project, he again returned to the camp of Mithridates. (Plut. Luc. 16.) Appian, who also relates the same story (Mlithr. 79), writes the name Olcabas.