Hmm, well what I would do is adapt an existing Stub template from another wiki. It can be just as easy as copy and pasting into your wiki's Template:Stub page, but you will have to delve into the source editor to do so. Here is a stub template from the Templates wiki. On this page, click on edit to view the source editor. Select everything on the page and copy it.
Go to your wiki and create a new blank page with the title "Template:Stub". Select Notice as the template type. Paste the Template wiki's code you copied from before into the source editor of this new page. Important: Also paste "Copied from [[w:c:templates:Template:Stub]]" into the edit summary. The Templates wiki would like this done for proper attribution.
You can preview the page and see how it looks at this point. Save the page and you'll have a stub template. There will probably be red links for pages that are missing, such as the documentation template. You can see how this template is done on the Templates wiki by repeating the same steps from above.
The best way to figure out Templates/source editing is to poke around in source code and try things out with preview. Though be careful not to make unintentional changes to pages while experimenting. That's where sandboxes come in!
You can customize the template the way you would any page I think, though I would recommend not using an image for the text. Being able the click on the links is an important function of the template, as it makes it easier for editors to navigate to the stubs category and whatnot. You can use a small image like how this wiki uses the stump image. There are many ways to implement something like that, though I don't know how you would do it with the Templates wiki template. If it were me I would try to figure out how other wikis did it and copy and paste it. This would probably require some familiarity with HTML and CSS, though.
you've really come a long way! In the last months, you have been essential in keeping the wiki running while Klei continuously bombarded us with new content and many of us were occupied with other stuff. Thank you very much for all your quality contributions and your participation in the community!
Skilled editors need to be provided with the right tools: If the other admins agree, I'd like to offer you promotions to the Custodian and Rollback user groups. This will allow you to fight vandalism more effectively, to mark edits as patrolled, or to protect, rename and delete pages and files.
your addition of a Wilson gallery page classifies as a large scale edit. Those edits affect the structural integrity of the wiki by changing high-traffic articles such as characters pages, creation and deletion of pages, and the renaming and moving of articles. In the last weeks, you have also been contributing several other large scale edits, including the separation of the Skins and Curio Cabinet pages into articles dedicated to single Curios.
Of course, it's obvious that your edits are only done with best intentions, however, you've failed to discuss the changes beforehand with this wiki's community. As stated in the Don't Starve Wiki Rules:
Do not make large structural changes to the wiki without talking to Administrators or at least having a discussion about the changes you want to make in the Forums. The wiki is a community effort, it is best to have the community drive the shape it takes, instead of individuals. Having discussions beforehand always creates better results for everyone.
This is a rule that's not just valid for fairly new users, in fact, even highly experienced editors and administrators should stick to it.
So in the future, please suggest changes that affect the structure of important pages to the community, so we're able to discuss them before actually implementing them. Thank you for your contributions to this wiki!