It is not legal to post patterns based on licensed characters. On your blog, free or not. It would still be a copywrite infringement. Especially if you were giving them out for free and the company who owned the rights to the character charged for images of the character. Unless you worked some sort of royalty program out with the company. Honestly, I wouldn't risk it. Those big corporations have some mean lawyers and they have no problem suing a little person into the ground and back. If it was not on the internet, just to select family and friends as like gifts or something, I don't see a problem. Its when you start offering the licensed things out to the mass public where the problem starts.
I hope this helped ^_^