Sunshine the teenage kitten turning MEAN!

Oh please help. We have a house/garage cat for a famliy pet. This was an extremely friendly lovely kitten. Purred 95% of the time UNTIL it started running in the cornfields and we assume hunting. When she comes back from the cornfields she is extremely agressive, ears pinned back, growls and wont let you pet her. Gives you the evil eye. Just plain NASTY! This kitten is my 5 year old sons which he adores her. She has turned from a warm, kind hearted kitten to a monster. What do we do?

Has she been spayed?

No...she has not been spayed...we were planning on it though.

Sounds like she might be injured and need a vet. Aggression is one form of response to pain. I would catch this kitten, get it to the vet have bloodwork and a check-up done. It is possible that if a cat stays outside for long lengths of time, they can revert back to a feral state, not wild, but feral, aggression is also a part of that scenario. But I would take this kitten to a vet if it were me.

We do plan on taking her to our vet on Monday. Maybe get some blood work and etc done. Can a cats hunting skills and etc really change the personality of the cat? From being wonderful to almost wild? She has been home sleeping in her bed for a couple hours. Still nasty behavior. Cant even pet her. Now...by tomorrow morning she will probably be nice again. UNTIL she wants out and then returns.

We had an aggresive cat and all the vet said was that some
cats are like that by nature

When you take her to get bloodwork done and checked out, if she checks out ok I would spay her right away. I bet that would eliminate most of your problems.

I have no idea what is going on without additional info, but besides Hissy's and Sicy's excellent advice, something else did cross my mind reading your post: who does she run into outside, if anyone? She might have met someone bad (maybe throwing something at her), and reacting to that? Just throwing that out there for consideration. This is not normal, especially for a once loving kitty.