I actually looked up pond scum on the interwebs to see what it actually looks like, and this comic's pond scum is the result of staring at pictures for a while.

The pond scum actually wasn't part of my idea on how May and Sam would meet, but then I remembered; Sam is a complete nerd with no athletic drives anywhere in his body, so why the hell would he be hiking out in the woods?

But then it came to me. He would be collecting pond scum for looking at and experimenting with.

Sam's backpack is actually based more or less on one of my old school bags. In reality, this backpack has a huge tear inbetween two pockets and has been shoved in a closet somewhere. But it was a good freakin' backpack. I still use it as my "suitcase" when out vacationing.