idk if there is an option to turn this off didn't dfind any so far, is there a way to remove the autocorrect tag thing ?

Like for exemple you search dragon type pokemon an existing tag you click on it but it has this arrow thingy that point to the "pokemon" tag & the search just become "pokemon" aka every pokemon

dragon_type_pokemon is aliased to pokemon. This is not autocorrect.

What you're talking about is an alias. An alias is used when either a tag has exact same meaning as another, or the former tag is deemed unnecessary, but a more useful tag can be informed from it.

The Pokémon types were aliased because keeping them would be super complicated, as they'd have to be manually entered as to not mess with posts that depict Pokémon with alternative types — and with terastilization becoming a mechanic recently, they're certainly not changing this any time soon.