can anyone ID this?

[Delphinus]

This started growing on my sump return pipe. It was a few mm before I left to go out of town, I thought it was a stray xenia polyp. But two weeks later, this is what it turned into. Definitely not xenia! Looks almost like a kind of lichen or some other kind of fungus you'd expect to find in a rainforest or something ...

Thanks to Canadian_Man for coming over and taking some pictures for me! Man I need a digital camera some day. Keen stuff!

As strangely as this thing appeared, it disappeared overnight last night. I imagine it got blown off the sump return pipe and landed somewhere I just haven't found it yet. There is another one forming on my other sump return though.

Any ideas???