This short guide will teach you how to give your Discord videos an animated thumbnail!
A text editor/IDE
Access to a webhosting service
Techincally, you aren't creating a video. Instead, you'll be creating an html file that will trick Discord into displaying an animated gif file as the thumbnail for the video.
Create a .html file. Open it with your text editor/IDE of choice, and copy/paste this line of code:
<!DOCTYPE html> <html> <head> <meta property="og:image" content="INSERT GIF HERE"> <meta property="og:type" content="video.other"> <meta property="og:video:url" content="INSERT VIDEO HERE"> <meta property="og:video:height" content="180"> <meta property="og:video:width" content="320"> </head> </html>