Originally Posted by bearwithfish
i second willows recommendation betta babby is incredible!!!!!!!!!
I appreciate the votes of confidence and support you offer, but unfortunately, this time, I'm afraid I am as clueless as the others.
With that said, I CAN offer some suggestions on how to attempt to figure it out, starting with tracing the origin of the plants it came in on. If they came from a lfs, I would check with them to find out where they ordered those plants from. If you can trace its origin, that might give you a better idea of how to find a positive ID.
My best guess would be closer to that of Kymmie... some type of insect larvae. Insects such as dragonfly larvae live in running water on rocks, etc. and feed on algae and leaves. There are also many species of beetles with caterpillar type larval stages. Find its origin and you can search the larvae of native insects, you may just find it.
If you find another one, get it into a sealed container (like the zip lock plastic twist top containers) and either take it to a local zoo or museum... or seek out a local entomologist. Many college campus's, especially those with an entomology department should also be able to help you, but they would need the specimen to examine first.
Sorry I can't be of more help. I specialize in fish, amphibians, reptiles, birds, dogs, cats, and small animals... but insects is not one of my specialties.
Oh... and a message to your dog from me: YUCK! ICK! EEEEWWW!