How common is it for cats to turn on their owners?

[dollface]

I've seen a change in Gizzy the last week. One day he is perfectly fine, shoves his head into your hand, screaming at me to pet him and then the next couple days he is hissing and running away from me.

Lately, he's been hiding in his sub box. Today he stayed in there most of the day. I pet him a couple times then went on about my day. About an hour ago, I was about to walk past him but I saw his claw dug into the carpeting of the box. I don't usually mind, but it looked like he was stuck, so I tried to remove it and he hisses at me! I blew in his face so I wouldn't get very mad and he did it again. I start raising my voice telling him to stop the hissing and bf comes out and asks what's going on. I explain I didn't do anything differently then what I normally do like when he claws the couch and I proceed to lift his paw off. Then bf tries to pet him to calm him down and Gizzy hisses at him too! That pissed bf off a bit. Then Gizzy got out and ran away. And when bf calmed down he was able to pick up Gizzy and talk to him calmly. He tried to get me to pet him but I didn't feel comfortable.

I've read the thread about Willy and I'm wondering if he's got a brain tumor that's causing these cujo lapses. Bf thinks he's doing what Forest does when sleeping; a nightmare of sorts where he forgets where he is and hisses, only Forest bites the bed he lays on.

He doesn't have the normal signs of having a tumor. So any insight would be great...