Here are all the 32×32 GIF animations included with PIXEL that was commissioned just for PIXEL by pixel artists around the world. Feel free to download them and remix them creating your own GIF animations. Alternatively, download all of them here.
Also here are the 64×64 GIFs included with SUPER PIXEL.
Use any image editor that can output a GIF, most folks use Adobe Photoshop and re-mix. And if you make something cool, please do share with the community on our Facebook page.