Cat has bump on head with spiked up hair coming out of it?

What can I do before i take her to the vet.

Is it warm to the touch? If so, it is likely an abscess. She'll probably need to have it opened and drained as well as to receive antibiotics. You may be able to get it to open on its own by gently putting warm compresses on the bump. Regardless, antibiotics are usually necessary to kill off the bacteria.

If the lump is hard, it could just be the base of your cat's skull where it meets the neck. I brought my cat in for something similar and that is what the vet told me. But it is better to be safe than sorry, so you should take your cat in just to be sure.

it was an abscess(she was bitten with a tooth by another animal the vet thinks), she had to get it cut out surgery,etc. she has a funnel on her head keeps trying to get it off.