Discuss: How to fight back against insecure, narcissistic, backstabbing colleague or superior?

Might get MS for this, but this is something I'm sure a lot of us here have had to deal with (myself included) so hopefully we can all have all meaningful discussion on this topic.

If you've been in Wall Street for >2 years, you are certainly aware of these kinds of people (let's call him Bob) and if you're like me who's been doing this for >4, you may have already figured out how to deal with the Bobs of the world, given up trying, or still trying to figure it out how! I am in the still trying to figure it out stage.

Bob is likely a man in his early-to-mid 30s. He was a mediocre student and not popular during his college and high school years. But who cares? He comes from a rich family and doesn't actually have to work for much. He graduates from his top 80 US university and then gets a decent job in NYC. He proceeds to later crush his GMATs (after over a year of studying) and gets into a top MBA program (e.g. NYU Stern). He leverages his newly acquired brand to break into the highly regarded world of investment banking. He joins the associate program FT at a bulge bracket.

Bob's confidence is sky high and he considers this a monumental accomplishment. He thinks he is 'cool' now and openly tells people he meets at bars and social gatherings he's an investment banker. He brags openly to his tiny group of 'friends' he had in college and high school, to the point that he starts pissing them off and distancing himself from that group. He thinks he's made his parents proud now that he makes $200K+ per annum and feels that he's entered the 1% of NYC and high finance.

But at work, Bob is a huge pain in the a*s to deal with and a highly narcissistic and backstabbing 2nd year post-MBA associate. He is terrible at his job so he covers this up by hiding behind top ranked 2nd year analysts and works them to death while he sits back and goes home at 8pm after picking up his Seamless. Meanwhile, his sycophantic behavior gains the love and trust of his VPs and senior bankers. None of this sounds problematic, except when behind the scenes Bob doesn't fight for analysts during bonus time. In fact, when the work product is good, he takes ALL the credit. When there are issues in the process, Bob blames everything on the juniors below him. The 2nd year analyst ends up getting a poor review while Bob gets top bucket. Rinse and repeat.

On one hand, if you try to fight back and hold your ground, you're wasting your time and energies trying to manage someone who can't be managed. On the other hand, if you don't fight back, you simply look like the weakling who just keeps his head down and does nothing but work hard (i.e. get no recognition). This is especially prevalent I think in a more boutique/middle-market environment, where you won't be working with huge armies of analysts and associates by your side.

TL;DR::: You have a super insecure, narcissistic, backstabbing colleague in your investment bank / F500 job / Big 4 accounting, etc. - how do you fight back against these types of people? BTW, this might not just be someone you deal with at work. Maybe it's a friend of a friend you meet at a large b-day party bar, you guys talk about what you do and say you work for example in corporate development at Kraft Heinz - the Bob in this conversation starts giving off a condescending vibe and brags he works at JPMORGAN (back-office, mind you), makes some idiotic and douchey comments asking if you develop the ketchup in the factory (lol). This type of Bob obviously has no idea what he's talking about and you say something back to hit the heart of his insecurities. How do you do it gracefully, or how do you do in a way that brings out their most insecure aspects and makes them go cry in the office bathroom?