Okay, well, either I've heard them called suffixes or I'm misremembering. 
Who knows? Maybe we're just thinking about them differently.
It depends on the code in the SVG animation. Use <style> to add animations via @keyframes.
What do you mean? Are you saying I have to edit the SVG code?
You will have to create the SVG code. I can help out.
Okay... how do I do that?
Find an SVG tool or vector based animation software, like Adobe Animate, then export each frame as an SVG file. Then, order them in a row then step animate them. It's a lengthy process, so, as I said, I can help out.
The only vector software I have is Adobe Illustrator. As far as I know, I can't animate with it (I may be wrong).
You would have to trace each frame individually.
I know what a suffix is, but I was confused as what you meant. They're called file extensions.
I was able to (manually) put the gif in an svg file, so here it is.
But it doesn't show up here.
Weird.
I've had the same problem with a post a while ago, when I was making help templates in "We need better help windows". I was trying to work with an SVG with images, and the images didn't show, so I just changed it to a PNG.
@starbox614's pfp is an animated svg. it can be animated with CSS.
here's a random one of mine that uses this technique:
Yeah, I actually made mine manually with a text editor after seeing this one.
It’s kind of complicated, so I would suggest downloading some and opening the in a text editor to see how they work.
A while ago I actually made a gif to SVG converter in Snap, but the files it produces don’t work in the forums.
:(
Why does a heart instead of a star go in and out of the box?
I partially made mine manually. I designed the actual image with an editor, but I themed it manually with prefers-color-scheme. That's why some people might see a colored version of my icon and other people as a black icon with white outlines.
Like me.
Wait. Your profile picture has colour?!
Yes. 
It only shows on system light mode. The black version is the system dark mode version.
