Has anyone else ever had this experience?

This is the first time this ever happened to me. I am a born cat lover and most cats love me. But a friend of mine's cat does not like me and I have been careful never even to touch him.

He tried to bite me twice previously, but this weekend he attacked me by leaping on my leg and biting me severely. His owner had to beat him off to get his teeth out of my leg.

What causes cats to do such a thing? He has bitten people before-his biting usually takes place in his house with someone he doesn't know very well, which tells me he is territorial.

But he has also bitten his owner recently.

I am now wondering if a cat can be mentally ill, like a human can,

This could be a medical problem. I hope he is up to date on ALL shots? Have you seen a doctor for your bite? Let us know what the vet and the doctor say!

I'm moving this to our behavior forum.

Whoa there.
If the cat has done this to someone besides you, specially his owner, then yes, this cat DOES need help.
A normal cat, will not attack a human, specially one who has seen you many times and you are a friend of the family.

I have never ever had a cat have a problem with me, except one little grey kittne, when I was much younger, I probably wasn't even a teenager yet. I was in my friends room with her standing by her mirror and her cat saw me, arched up its back, pupils dialated, and started to circle closer to me, I have no clue WHY this cat did this. This cat had seen me there earlier that day and not cared.
I had to like back away and jump up on my friends bed and then dash our of the room, because the cat was blocking my only way out.

Even though a cat is small, a cats bite can be VERY bad, because of all the bacteria in their mouth. A trip to the vet is in order, as well as it's owner sitting down and doing some serious thinking as to what may have caused her cat to do this on a mental/emotional level.

Cats that have been mistreated in the past will react to certain types of people. Ours hates women and hides from them. She also senses slight tension in the atmosphere and runs upstairs hiding.

Some cats react differently such as agressively, nervous etc when frightened. Maybe you wear a type of perfume the cats dislikes, their smell is 4 times better than ours.

To curb this nasty behavoir I would suggest squirting the cat with water from a childs water gun. So if he goes to bite you, squirt him once, eventually he'll stop attacking you. Then you could maybe offer him food, say small pieces of chicken for him to come round to you.

Oh, I also wanted to know if his owner had given that cat any illegal drugs. I'm not saying your friend is that type of person, it's just a question. A lot of cats, animals in general, can act very strangly, out of character almost, if someone gives them pot, or alcohol, acid... any type of substance.

Try not to take it too personally yet, as the cause is very undetermined. I like Bunn's idea of working with him, to get him to come around to you, if you feel safe doing it.

We had a feral cat we cared for who would attack like this. Once we put him on St. John's Wort (herbal Prozac) and implemented a very strict behavior modification program, his behavior improved to such a degree that he was able to be adopted out to a family. But, it took a whole lot of work to get the aggression under control! So...perhaps it is like a mental illness, or it could be extreme territoriality or dominance issues. Whatever the cause, the behavior can be changed!

Keep an eye on the bite...deep cat bites can cause wicked infections!

Yes, I did go to the doctor who gave me an updated Tetanus shot, antibiotic prescription and even had my leg X rayed. She said that many times a cat's tooth will break off in your skin. Of course, I knew I didn't have any tooth in there.

My friend's cat has seen me before, but I have been going there more often in recent months. She did threaten to have it euthanized when it bit me, but I think she is going to have a Vet consult.

She is a very responsible person and I know the cat is up to date on vaccinations and would not be on any unusual drugs. I think it is just plain domineering and territorial.

This usually has happened with people it doesn't know well coming in to her house.

From what I understand this cat has always acted strangely.

I do suspect there may be something about my body scent that this cat does not like.