If they were declined it's probably because they did not appear as what a hybrid is in the group! For example, bat ponies don't classify as hybrids in the group, we accept really anything that is visibly different from the standard pony species! (so no: pegasus, earth, unicorn, bat, vampire). If you feel like there has been a mistake please feel free to resubmit the works and we'll look at them again! c: