Where does the translation for hats in the Winter Bash page?
I can't find them in transifex.
I see the link in the bottom of the page:
view hat descriptions in English / translate hat descriptions
but I can't understand where they come from.
Winter Bash doesn't use transifex. The translations to Portuguese, Japanese, Russian, and Spanish are done by the community managers of the respective localized Stack Overflow.
That said, if you notice a typo or something like that, feel free to report that as a bug (it wouldn't be unprecedented).
Translations for all international sites' hats are done in a special hat-file. You cannot find those strings on Transifex. If you find typo or have any other suggestion for the translation, please, ping an appropriate CM in chat.