Blue Moon

Embedding images on your profile works the same has embedding them in normal posts. You can either copy an image from the internet using "Copy Image" and just paste it into the profile editing box, or you can copy the image URL by right clicking the image and clicking "Copy Image Location." Then, you'll want to click the Image button in the editing window (see image below) and enter the URL:
 
 

 
 
If you want to use an image stored offline on your computer, you'll need to upload it to the internet somehow. I personally use Imgur, but there are many others you can use. Just search for "Image uploader" on a search engine, and you'll find something.
 
Hope this helps!

In order for .GIF files to work properly as an avatar, they must be, at most, 150 x 150 pixels. The .GIF file you're trying to use is 250 x 250 pixels, which is too large.
 
I went ahead and resized that .GIF file to the proper size; it should work now. Let me know if this helps!
 

Only two embedded videos are allowed per post; any videos outside of that limit will be shown as links instead.

No, you just upload the GIF file the same way you upload a normal image for your avatar. However, you need to keep in mind that GIF files tend to be larger in size despite their dimensions, so try to keep them relatively small (the max file size is 100 KB).

It's possible that the file size of the image you used exceeds 100 KB (i.e. the file size limit for this site), and that would make the GIF not work correctly.
 
Try using this smaller version of the GIF; it should work:

New moderators are added to the forum only when deemed necessary by the site's existing staff. There is no sign-up process or application system for moderator positions; it is an invite-only job, and one that requesting or attempting to 'sign up' for will only result in disqualifying yourself from. 

We strongly believe that the best moderators are the ones that have very little actual interest in being a moderator in the first place, and instead accept the position solely for the sake of helping to improve the community as a whole.

To be honest, it's a rubbish job that involves a fair bit of stress and work. You don't want to be a moderator.   -MLP Forums FAQ