What is a "Chover Chaver"?
Rashi #1 and Targum Yonasan: Someone who gathers snakes, scorpions or other Chayos 1 to one location.
Rashi #2 (in Yeshayah, 47:9): It is a Lashon of witchcraft.
Sanhedrin, 65a: Irrespective of whether they are large or small - even snakes and corpions. See Torah Temimah, note 60.
What is the difference between "Ov" and "Yid'oni"?
Rashi (citing Sanhedrin, 65a) and Targum Yonasan: "Ov" is a kind of sorcery that is called 'Pitum', where one raises a dead spirit 1 to under one's armpit (or to between one's joints ? Sanhedrin, 65b), from where it speaks; whereas "Yid'oni" places the bone of a Chayah called 'Yado'a' into one's mouth, where it speaks by means of sorcery. 2
What constitutes "Doresh el ha'Meisim"?