Yeah, we tried with this last one and got it halfway unrolled before it caught and tore. Oh well, I'll just keep trying

And hammerhead: Poo typically is dark and tube-shaped...like any other animal poo, and usually has a white/yellow powdery urate at one end or nearby. Size varies a great deal from a tiny pellet to a log as big around as the snake. Sometimes it can have a furry look from the bits of undigested fur, but it always should look like poo.
I believe if you do a search, some people have posted pictures here and there on the forums