Spiny Oak-Slug Moth Caterpillar

I found better picture :-)

Thank you very much bayucca. I added ID. It is exciting to get to know all these wonderful creatures with names :-)

Thank you very much for your nice comment beaker98. I hope I will find out what this is :-)

What a strange looking little guy! Reminds me of something from the ocean, like a sea cucumber or something. I have no idea what that may be. Really cool though!