How to upload a gif as your osu! profile picture
Link to the gif resize below:
https://ezgif.com
Summary: Resize the photo to a 128x128, make sure its under 88kbs, save the resized photo and make sure its put down as a .png, and make sure to check "all files", then upload it to the old osu! website.
Oh, and also I found out that its not a bannable offense to make it a gif, unless it is of course, inappropriate. Have fun!
If anyone has questions, please feel free to ask below in the comments section.