What's a JS?

Oh, Java Script

How can I add it? I don't have any experience with Fandom Bots.

As you said, JS stands for JavaScript, which is sort of a programming language used widely on websites.

Users on Fandom are allowed to use JS snippets to add functionality or improve user experience, and each user has dedicated pages for their personal JS. There are also JS pages for an entire wiki, controlled by the local admins but more limited in what is allowed.

Fandom developers wiki hosts dozens of JS scripts made by users for other users to use.

(Just to complete the picture, there is also personal CSS and wiki CSS which can control and improve the way the website is displayed.)

Scripts are not bots. This one specifically does something that can fit a bot account, but you can also use it on your main account. I suggest you read through the instructions on the page and try following them, and then if you still have questions you are welcome to ask.

If the off-topic images are the users' only contributions, you could use Nuke.

Thank you all for the advice! I followed the steps and enabled batch delete :)

So I entered on of the images into batch delete and got this error message.

Failed to delete Lf.jpg: missingtitle

Try including the namespace: File:Lf.jpg

I did what you said and it worked. Thank you!