Any idea what this is?

Health and lifestyle for my dog!! My husband and I noticed what looked like a small shaved but on our dogs paw the other day. There didn’t seem to be any mark apart from a slight green tinge which I thought was just grass stains from running about. I’ve just looked at it again and there is now what looks like dried blood. I’ve never seen a tick bite but going by google pics I don’t think it looks like that. It also doesn’t seem to be bothering him. Any ideas?!