Board Thread:Support Requests - Designing Your Wikia/@comment-27469609-20151226153048/@comment-25357967-20151226154543

Yes, simply add a pipe symbol (|) after the name of the category. Any text added after the pipe symbol will replace the category name.

Example
becomes: and will display as Avenger Games in the navigation bar.
 * Category:Avenger Games
 * Category:Avenger Games|Avenger Games