How can I download a Wikia for offline reading? Is there a specific service that I can use to download a Wikia? Once done, how can I read the downloaded file? I don't need images or other media files, but HTML formatting will be nice!
Each Wikia site should have an XML dump available on their
Special:Statistics page. You can get there directly by following this format:
www.<wikianamehere>.com/Special:Statistics Navigate to the "Database dumps" header and select the dump relating to current pages -- you can safely ignore the one regarding page history if you simply want to read current material.
The XML dump is essentially one large file that includes Wikia's pages source (in wikitext format), but not images. If you are on Windows you'll need an archive utility, such as 7-Zip or WinRAR, to extract the file.
I am less familiar with a specific reader that will assist you; you may simply want to install MediaWiki locally and import the XML dump. Failing that, I would recommend taking the second half of your question to Super User.
Anthony Neace answer is good but you will have to import each specific page separately and manually.
I found this general dump but is rather old and missing some pages (if you can find other that has more than this feel free to post it here): https://archive.org/details/wikia_dump_20141219
And for offline explorer you have this choices:
If you look at the answer of this question: How to dump a MediaWiki for offline use? (A) you can see you can use Wikitaxi, XOWA both have dump importing capabilities.
You can see other applications that can import dumps here:Wikimedia projects offline explorer alternative to Wikitaxi?
All Wikia text is available for easy download. You can download the database. You will find links at the end of the statistics page---Special:Statistics. Only the text is included, not the images. The download is in XML format, so you need to be able to import that into something to read it offline.