I came home today and noticed two patches of this stuff in my flower bed. I recently put down new mulch and I just started watering my lawn again. I live in Texas.
1) Is this a fungus?
2) Is it harmful?
3) How do I get rid of it?
It's not harmful. In a very few places, one phase of this, when it's transparent "slime", is eaten. No thanks. It made (non)fungus of the month in 1999 - what an honor!
As for getting rid of it - there's no need, but if you want to try, use a shovel, not a hose. Spraying it will just spread the spores around.
I just talked to the guy that handles my lawn and he said that this is common with new mulch. As the wood decomposes, you can sometimes get different types of bacteria and fungi as a result. He told me that he's seen it before and says that you can just remove it.
Also, from what I hear this isn't harmful to your shrubs either, so that's a plus.