I'd also make "reference sheet" lineart for me to use and so people could make their own if they didn't want to/don't draw.
I'd include info like: A picture, likes, dislikes, accessories and other things like that! Maybe even a cub/teen/adult thing!
Sorry if this is the wrong place to put this XD I just wanna get some feed back before I go ahead and make something that no-one is interested in

Maybe it could even be a sticky thread?
"Adoption Centre" or something?
EDIT: I attatched a female reference sheet, to give an example of what it'd look like.
EDIT 2.0: Done the male ref sheet too!
I thought another possible way of doing adoptables could be a "batch" or "set" like this - http://gothic180.deviantart.com/art/Noa ... -141872691 but obviously with lions/other african animals. ^^