Orcs on both sides

[Ancalagon]

I just finished reading the Silmarillion again, and during the final chapter, reading about the Last Alliance, I noticed this interesting point; the book says, 'All living things were divided that day, and some of every kind, even beasts and birds, were found in either host, save the Elves only.' This led to me wondering if there were any orcs that maybe rebelled or fought against Sauron, or if anybody had any evidence supporting or disproving this theory? Thanks in advance