Every office has one (or two, or more). You know the types. Those toxic coworkers who only look out for Number One, no matter what the cost to their coworkers or the company. The kind who, when you are next in line for a promotion, raise, or simply the next pat-on-the-back from the boss, won’t hesitate to steal your thunder by brown-nosing their way into the boss’s good graces. Basically, they’re the people who will step all over you and your coworkers if it means getting what they want (with as little work as possible).

Is it possible to get ahead when your office ne’er-do-wells are trying to bring you down? Yes. The trick is recognizing these negativity-spewing colleagues before it’s too late. Understanding these dysfunctional types is a key to successful human resources management.

Greed, laziness, selfishness, and backstabbing are all-too-common in many company cultures. Often, the people who personify these behaviors within organizations step on the backs of colleagues who are just trying to put in an honest day’s work—so the villains can get ahead or get out of pulling their load. Let’s call them out.

If your memory is flooded with all of the toxic colleagues you’ve encountered in the past (or are dealing with right now), you aren’t alone. The days of simply having to grin and bear them are over. Here are nine common, crappy colleagues to watch out for and how you might be able to work around them.

The Politicians

Promotions based on merit are not the province of these schmoozers. Instead, they participate in pernicious office politics—popping into the boss’s office every five minutes, declaring their indispensable worth. The Politician is consumed with company politics. Her work life becomes a game in which she is constantly trying to “win” the next job, the next promotion, the next project. However, she spends little or no time fulfilling her current responsibilities.

How to protect yourself? If you’re looking to earn the promotion you deserve without playing the office politics game, first evaluate your boss. If your boss has a huge ego, then the Politicians will be tough to beat because they excel at stroking egos and kissing up to get what they want. If your boss isn’t an egomaniac, she will soon tire of the grandstanding.

Once you have determined the boss’s motivating factors, you can adapt your behavior to combat the Politician without losing focus on your job. State the facts. Documentation and accountability are to the Politician what kryptonite was to Superman. Create a paper trail. Save all of your emails and voicemails, if possible. You may need them for later reference.

When it comes to documentation, though, keep in mind that Politicians abuse email. They ask you to forward documents to them for review, then send them on to the boss without your knowledge. They create the perception that they did the work. A favorite tactic is to reply to you—“cc”-ing the boss, of course—but taking credit for your work. Make sure the information stream to the boss flows directly from you. Don’t give the Politician an opportunity to put her name on work that originated with you.

The Roosters

Roosters want to crow a lot about themselves; they also like to roost on the fence to avoid making decisions.

The Rooster suffers from egomania. This affects his ability to make decisions. If a Rooster makes a poor choice, it’s a huge bruise to his ego. At some point, he may have to admit he was wrong. Fear of imperfection keeps the Rooster on the fence. He rarely, if ever, makes a decision. If he’s lucky, someone else will make it. If he waits long enough, the decision will make itself. Either way, the Rooster’s passive approach allows him to maintain deniability.

The Rooster is quick to assign blame. He seems to be more concerned with finding out who is responsible for the problem than actually trying to fix it or find its cause (not that he could fix anything anyway; that would involve actually making a decision). The Rooster prefers to ignore problems, hoping they will go away.

How to protect yourself?  Either force the Rooster to make a decision, or tear down the decision fence and watch him run around aimlessly. Whichever choice you make, you will need a lot of patience.

The Funeral Directors

These are those folks who live on negative energy and are motivated by crisis. Drama drives their days. Although they usually have ample time to complete their assigned tasks, they procrastinate or otherwise delay progress until there is a crisis and something “just has to be done.” Any task you give them will eventually become the “end of the world” until it is accomplished.

How to protect yourself? When you work with a Funeral Director, pad the schedule. Make sure that the deadline you assign is earlier than the actual deadline. This will ensure that their crisis does not become yours.

The Tattletales

Who keeps the office rumor mill going? How does your boss finds out about every little mistake from you and your colleagues right after it happens? Look no further than your office Tattletale. Some folks might strive to be bearers of good news; not the Tattletales. They deal in negative office rumors and gossip, or in any other information that they think they can use to get ahead. They love to share bad news—as long as it is about somebody else.

How to protect yourself? Keep your mouth shut. Don’t disclose anything you don’t want everyone to know about. The only thing you can trust about Tattletales is that they will disclose any information you tell them if doing so will give them a leg up in the company. Remember, anything you say to them can and will be used against you.

Tattletales have some value. If you want to spread information, just tell your office Tattletale and ask him to keep the information confidential. He won’t be able to resist the temptation, and your message will quickly spread throughout the company.

The Points Shavers

We all know someone who is a Points Shaver. She keeps score on everything. Anything she does for you is recorded on her mental scoreboard, and she expects to be repaid at some point—in the near future.

Points Shavers seem to remember what they have done for you and forget what you have done for them. Whenever you ask for a favor, they start in on a long list of what they have done for you in the past, and how your new requests will increase the debt you owe them. They’ve forgotten how many times they cashed in on their favors.

How to protect yourself? When dealing with a Points Shaver, keep in mind that the score is never tied. Don’t bother keeping score unless it’s worth your time. The best way to keep your sanity may be to avoid the Points Shaver altogether.

The Networkers

Surely you recognize the Networker—the person who spends more time networking than actually working. They believe that the road to success is about whom you know, not what you know.

I’ve watched people do nothing but network all day long. One guy worked from 8:00 a.m. to 10:00 p.m. almost every day. Initially I thought he was a very hard worker. One afternoon, a few of his coworkers showed up at happy hour, and I asked them why he worked so much. It turns out that he was spending the entire day walking around the office, socializing with everyone, then doing his work after hours.

How to protect yourself? Don’t get trapped in the Networker’s web. Networkers name-drop and appear to be connected. In reality, they are time thieves. They burn up a lot of your valuable time with meaningless office chitchat. It doesn’t take long for everyone to get tired of them. Hanging around them will not add much to your value.

The Taskmasters

Have you ever come across someone at work who spends all of his time worrying about what everyone else is doing, at the same time complaining that no one else in the company ever does anything and he is saddled with all the work? This is the Taskmaster. Taskmasters are quick to assign tasks to other people to avoid having to do anything—and yet as soon as a task is completed, somehow the Taskmaster is there to take credit for getting it done.

The Taskmaster constantly works to create the perception that he is so busy that he just couldn’t possibly work one more thing into his day. In reality, he has a lazy streak a mile wide, and he works harder to get out of work than most of us do to get our work done.

How to protect yourself? Beware. Keep him at a distance or you will spend your days doing his job.

The Wakeboarders

Watch out—coming through! Wakeboarders are similar to Taskmasters in that they like to pass their work on to others. Unlike Taskmasters, Wakeboarders hide their BS behind an outgoing personality. Coworkers like them, so they are more willing to help, and the Wakeboarder knows this. She spends a good deal of her time socializing, not to network, but to find gullible coworkers to whom she can pass her work.

How to protect yourself? Steer clear of Wakeboarders. Although Wakeboarders are typically good employees and may produce high-quality finished products, they leave a wake a mile wide as coworkers bust their humps to help them complete their projects. They spread discontent in their wakes.

The Office Flirts

I think we all know what this is about by now. But look out for Office Flirts who do their flirting 21st-century-style. You may become involved in an email back-and-forth or IM conversation that turns flirtatious before you even know it. Or you could receive some questionable correspondence after becoming the Office Flirt’s friend on Facebook or another social networking site. Bottom line: keep all of your office conversations professional—whether they take place by the water cooler or online.

How to protect yourself? Just don’t get involved. End of story. Nothing good can come from it. Don’t even think about it!

—Blaine Loomer has consulted with many companies over the years, from enterprising individuals to some of the largest corporations in America. His book is Corporate Bullsh*t: A Survival Guide (Mitchell Publishers Inc., 2009).