Have you ever wanted to tell a co-worker off, but 'cant' because you all need each others' help?

...to a certain extent.

I have a co-worker who says things in such a snarky, condescending way. I get tired of it.
I refrain from saying some things because it's like, I already know what kind of reaction I'm gonna get.
I want to tell her about her fat self but we work closely. I might have a question about work and she's the closest. I don't like her anyway.