Board Thread:Support Requests - Designing Your Wikia/@comment-24658545-20141016184632/@comment-452-20141017120601

Yes. Those three examples all do it differently, so you can choose between:
 * http://tardis.wikia.com/wiki/MediaWiki:Common.js/mosbox.js
 * The whole script, although you might like to edit it down a little.
 * http://finalfantasy.wikia.com/wiki/MediaWiki:Common.js
 * Search for "articleinfoicons"
 * I would personally remove the (!ifGroup("staff")) part which is causing it to not show up for staff, because doing that is deceptive, and likely against the TOU to hide something from Staff, even though it's permitted to do it.
 * http://spongebobfanon.wikia.com/wiki/MediaWiki:Wikia.js
 * Search for "Extra Chat Stuff"

Incidentally, these are the only three wikis on Hub:Big_wikis that add sidebar content, although there are likely to be a few smaller wikis who also do it.