Have you ever brought this up with her or anyone else? This seems like a fairly generic case of "colleague creating a toxic environment".

If she actually goes ahead with that petition or hell, even if not, a talk to HR should see her getting fired within minutes rather then hours. This could easily be grounds for a discrimination / hostile workplace lawsuit (IANAL, obviously).

How long has this been going on? I usually suggest ignoring childish behavior in others. But if it continues, you might consider telling her to f*ck off.

"Do you know, how to deal with this?" VTC since it's up to you to decide what you want to do about this and what you're comfortable doing. I'd start by maybe not letting her walk all over you as that's a necessary precursor for any further action you might take.

I thought it was something about panties but after rereading it's about a petition.... she has jealousy issues of one sort or another if she is singling you out for this treatment. Tell her she's not the beard police.

en.wikipedia.org/wiki/Workplace_bullying_in_academia

... I'd consider dyeing my beard of a very bright color (think: bright green, or purple) just to annoy her more and see what she is going to do...

Some standard responses for these kinds of people you might want to think about (not necessarily say out loud) for your own personal amusement: 1) "Since when is my [feature] your business?", 2) "When did I ask for your personal opinion regarding my [feature]?", 3) "Your opinion of my [feature] is irrelevant to me", or the big gun 4) "My [feature] looks just as terrible as your [feature, e.g. weight, height, etc.]". Or maybe she has a crush on you and (incorrectly) thinks she's just being a "playful tease"? Joking aside, go to HR now as suggested in the answers.

When you have gone to HR, could you please come back and share with us what they said? Thank you (btw, which European country?)

If you have been "smiling and joking" up to now, it is possible she thinks this is a long-running "joke" at your expense. Stop smiling and joking and and inform of your true reaction and ask her to stop. Be serious, be calm, be polite, and most importantly be direct.

@pay I will give you a pass to "say it", because I am wondering what on earth you are talking about? You can always delete the comment later.

@nocomprende The reason I don't bother saying it directly is because we're not at a state of collective maturity in 1st world societies that allows us to discuss these things objectively. A few other people have pointed out (with upvotes) that there is a blatant gender bias here, so I will at least admit that. Beyond that I see nothing useful coming from that particular line of discussion, at least not for another 5+ years when it will become a relevant and useful narrative.

@pay OK. I will wait the 5 years. Cheerio!

Are you an employee or a student? Who you talk to potentially depends on your status.

Tell her that you will have a shave when she gets around to doing the same

Joke: Complain to HR that she is referring to your beard workplace.stackexchange.com/questions/75595/…

"I will shave mine if you shave yours".

A beard and bald head in a math department? Wow, unheard of ...

A bit of search shows Georg Cantor had a beard and bald head. Of course you could shave and come back as Leonhard Euler. bing.com/images/…

"just shave that, you look terribly" "Just stop the harassment, before I file a complaint." Flat, level voice.

"Woa, you must have a really boring life if you go having strong opinions about people that don't give a fuck about you"

What ever you do, be very careful to what you say. With the slightest wrong word, she could be the one going to HR.

I swear 99% of the questions on this site can be answered with the same response. "Grow a pair, and be honest with her. Don't get angry, don't try to be smart, just stay calm and grounded and tell her what you told us." Also want to add that 'growing a pair' is not about being 'tough' or 'angry'. It's about being honest and vulnerable, which takes more courage.

@Frammo did you really read ? She's just harrassing him! Do you really think that just telling someone like that to stfu will change something ? Something like that have to be handle by HR.

@Walfrat - Did you really read my comment?

@Frammo I did and i clearly think that woman just won't listen, i don't see how someone that can go this far will just stop by 'hey i like my barb and that won't change'.