Hammerhead Worm (land planarian) (Bipalium kewense)
Folsom, CA. I have found quite a few of these around my yard since 2005. Being new to the CA area I was unsure of what they were until I found this site. The head has a considerable grip once it holds onto something. They were first spotted in 2005 under my hot tub when I removed it (a wet damp place due to water leakage). Since then I can find them in my yard under composting leaves under plants and shrubs.