yes it is a pychic attack move.
Zen Headbutt is not a TM. It can be learned by leveling up, breeding, or by the Move Tutor.
Extrasensory. Zen Headbutt is a physical type move so therefore it is subject to Pokémon that have Static, Rough Skin, etc, but Extrasensory is special type move. They have the same power so that doesn't mean anything. Also, Zen Headbutt has an accuracy of 90 while Extrasensory has an accuracy of 100. And they both may cause flinching. So therefore extrasensory is better.
Zen-Headbutt is not a TM, but its is a move that some Pokemon learn naturally. This move can also be trained by a move trainer for heart scales to your Pokemon.
no
Slowbro can use Zen Headbutt.
bagon learns zen headbutt at lv.37
it learns zen headbutt at level 40
Rest, Sleep Talk, Earthquake, and Zen Headbutt.
I believe Cranidos learn Zen HeadButt at Lv.33. However, he learns Head Smash at Lv.43, 10 levels higher than it learns Zen HeadButt.
it learns zen headbutt when it turns level 36
Arbok's weaknesses are Psychic and Ground-type moves. Since Arbok's Defense is lower than Sp. Defense, you should try using physical Psychic or Ground-type moves such as Zen Headbutt, Psycho Cut, Dig, Earthquake, Magnitude, et cetera. Do not use Grass, Poison, Fighting, Bug, or Fairy-type moves for those are its resistances.
Dragon Pluse Fly Or Any good flying type move Flamethrower Or Heatwave Earthquake Or Zen Headbutt.