He just had a vet visit not too long ago and they told me he looked good. We found him in August, starving and injured...He's always been aggressve. But when he was neutered he calmed down a bit. He still got cranky and would scream and smack everyone now.

Then last week it escalated. He won't play with the other cats, he's constantly beating on them and hissing/spitting or screaming at them. He'll let humans pet him but he'll scream at us. Usually we stop petting him, he did it to me tonight and I stopped and said "What is wrong with you?" and he smacked me in the face. No claws extended but he's just not a happy cat.

Any ideas at all? I'm going to make another vet appointment if I can't figure it out soon to rule out him being injured or sick. I have no idea how old he is, but he acts like a grumpy old man. =P
he seems to go through this every now and then now that I think about it. Each time he seems to be a little worse about it though.