That's a Bipalium land planarian, known as "hammerhead" or "broadhead" planarians. They are invasive and predatory, and a real danger for earthworm populations.
The animal of your video resembles a little bit to Bipalium cf. fuscatum I recently observed in Kyoto (Japan), but I think a examination of the specimen is almost mandatory to identify these animals (I didn´t have the oportunity to do so in the lab, so that´s why I used a "cf" status for my specimen). Here it is a photograph of the specimen I said: http://www.asturnatura.com/fotografia/fauna-invertebrados/bipalium-cf-fuscatum-1/23995.html Please, be aware that I used flash for taking the picture and it affected the colours.
Please, do not take this message as a positive identification, I just give you some information to help you to identify the specimen. Good luck!