What type of holly is this?
There are more than 480 species of Holly (Ilex sp.) making identifying your holly seedling nearly impossible, except by an expert in this field. It would be much easier to properly identify once it has started fruiting.
After this has occurred, if you wish, you can either send in a current photograph to Ask an Expert or take a photo and possibly a cutting to your local OSU Extension office. In Clackamas County, 200 Warner Milne Road, Oregon City, OR 97045. Please call 503-655-8631 before arriving to verify current hours.
Best of luck and happy gardening.