The Wiki does have a list of custom pets.
It's under the Custom Items/Gears category, here, which is linked from the front page of the Wiki.
http://www.pandoraonline.net/heRO_wiki/i...stom_Items
P for Pets.
That shows all the custom, obtainable ingame pets.
Donation pets are different altogether. I expect Pandora has a list of which ones people have had, but pretty much any mob can be turned into a pet. You're not restricted to a list of what RMS has available or anything.
Obviously there are some restrictions though, with MvP mobs, etc.
The pet will have the mobs sprite, eat candy, but, if it's stats are higher than a certain amount, it'll be reduced to a preset of stats we have.