The SpongeBob Wiki has a guideline regarding the use of image galleries — collections of episode screenshots are no longer allowed on galleries due to potential fair use violations.
Help:Image
From the SpongeBob Wiki, the SpongeBob encyclopedia
All images added to this wiki must be released under the public domain, qualify as fair use, or be used with the copyright holder's permission. This wiki's content licenses are listed under the copyright tags category and can also be selected with the upload form.
To use an image in an article, you simply surround the full name (including the "File:" part) in double square brackets:
[[File:Patrick.png]] will give you:
You can resize by adding the size in pixels between two pipes:
[[File:Patrick.png|50px|]] will give you:
You can make an image a thumbnail an image by adding "thumb" in the same way. If a pipe is there from a previous variable, you don't need to add another:
[[File:Patrick.png|50px|thumb|]] will give you:
This is automatically formatted to the right of the page. You can change this by adding "left" or "center":
[[File:Patrick.png|50px|thumb|left|]] will give you:
Anything after the last pipe becomes the alt text or the caption:
[[File:Patrick.png|50px|thumb|left|Alt]] will give you: Alt
To link to a file without showing it on the page, you can use "Media" instead of "Image":