Old MacDonald had a What?!!?

Braxton loves to read and sing. One of his favorite songs is "Old Macdonald". However its been a very long time since that farmer had anything resembling a farm animal. Take this afternoon for instance. Old Macdonald had some grass, an octopus, some knees, some feet, a big fish, some glue, and some clouds. Does anybody know what kind of sound any of those make? The only one I knew was the big fish. I was totally at a loss for glue, knees and an octopus. I'm not quite sure where he gets this stuff.