These people have worked on Valley of Unicorns or its Wikia in some official capacity. It's possible that you may need to contact them if you have questions, concerns, or broken things.
The Matriarch, aka Kristen, is the creator, main admin, and sole coder of Valley of Unicorns. She's the one to contact if you have issues with your account, or if you have discovered a severe bug whose details are unwise to post about in the public forums.
Valk and Ems are the site's two Directors. In addition to moderating the forums and other communication features, they're the ones who approve customs and make the majority of decisions relating to creative direction and proposed gameplay changes. They're also happy to answer questions about the site, and without their knowledge and assistance this wiki wouldn't be possible.
Gusty was previously a Director before stepping down from the position.
Official site artists include the three abovementioned directors, as well as ShinePaw and kitestrings. They've created the majority of art on the main site outside of user customs, and Gusteon has also kindly contributed graphics to the Wikia. As players of VoU, all of them except ShinePaw have also created several gold and silver customs.
Harmony is not, never was, and likely never will be a staff member of VoU itself, but she still has an important role as admin of this Wikia. If you have any questions or concerns about the wiki, she's the one to contact. If she hasn't done anything for the wiki in a while, blame her lack of spoons and please be patient.