What is it? Where can I see one in use? Are there ones available for purchase or do I really have to make my own?

Hi

The CPO is a overlay drawn by yourself or another person and used as the pet image instead of the official subeta art image of the pet.

Most of the Pet Spotlight pets have a CPO. You can see them at the previous winner page. If you want one, check out the art market subforum for topics of subetans which draw pet overlays. ^^ (For sP, CSC, € or $)

Also the Pet Profiles subforum is for CPO and/or Profiles.

a custom overlay will replace all instances of your pet's image across the entire site. however, if you only want to replace your pet's image on their profile, you can do that for free by adding the following code to their description:

{background: url(IMAGE URL) no-repeat;}

as mentioned, you can either create the image yourself or commission an artist. if you're looking for an edit of official pet art, you can find artists in the pet profiles section of the profiles & graphics market, but if you want a fully custom drawn image, you're better off asking in the art market.

additional information & rules pertaining to custom overlays can be found on this page.