Many entrepreneurs believe all money is created equal. As long as somebody recognizes their million dollar idea and writes them a check, the source really doesn’t matter. Most angel investors are pure, but there are some exceptions to watch out for:

1. Shark angels. This is the ultimate bad guy whose sole intention of getting involved in early-stage investing is to take advantage of what they believe is the entrepreneur’s lack of financial and deal-making experience. If the term sheet process turns to pure torture, it may be time to respectfully bow out.

2. Litigious angels. The litigious investor will look for almost any excuse to take you to court. This type of investor never really focuses on the returns your company can deliver, but instead tries to make money by intimidation, threats and lawsuits. They know you won’t have the resources to fight them, so they count on you “caving.” Keep your attorney close by your side.

3. Superior angels. A number of successful business people, some of whom become angels, develop the belief that they are destined for greatness because of their clear superiority over everyone else. These are usually overbearing, negative people who are hypercritical of every decision you make. Don’t be intimidated into bad decisions.

[read the rest at Fortune.com]