Here are some pixels I made when there was an eeveelution event at a forum I was part of in the past. The event was about fansites, not pixels, I just made these pixels for fun because they matched the general theme of eeveelutions. I also made a Jolteon fansite for the event itslef.

To adopt a cute little eeveelution, just display the gif on your site and link it back to https://miliblue.neocities.org or https://bluebatart.wordpress.com Please remember to link it, otherwise that's not adopting an eeveelution, it's just kidnapping an innocent pokemon. Here's an example of what the codes would look like:

<a href="https://miliblue.neocities.org"><img src="IMAGE_NAME.gif" alt="EVEELUTION_NICKNAME"></a>