How come in the episode:Abra and the Psychic showdown" Ash picks a ghost type pokemon? cant he pick a dark type to defeat Sabrina?
Dark-Type Pokemon were introduced in Gen 2 and at the time Ghost -Type moves had no effect on Psychic-Types at all which is weird why in the anime it says Ghost-Types had an advantage. So Ash couldn't capture a Dark-Type Pokemon at the time.
As of gen 8, yes, technically.
In let's go Pikachu and Eevee, there are regional forms that you can acquire. You can get Alolan Raticate, Persian and Muk. If I forgot any, please tell me.
You can also have a mega gyarados.
Dark types werent Introuduced yet....Until Genereation 2 even then it was a glitch that effect that type macth up thing...The other types he couldve Choosing were Bug for that Gym but he didint have Butter free anymore so its normal that he used haunter....
FUN FACT: All of Physic type weaknessses are fears in real life SomePeople are afraid Bugs the Dark and Ghost that is truly a fun fact..