thats a tough one without a Google account to get in. The last resort is a factory reset, via settings in the hidden boot menu, which should hopefully unlock it as new.
You could try the blackhole access. If it is still there.
Phones: Use a hole to disable your lock If it is a phone -- i.e. if you can give it a voice call -- you might be able to use a "security hole", as described here: Call yourself from another phone, answer, hang-up, directly after hanging up start pressing your buttons like a madman for <30-60 seconds ending with your home button (might take a while to get the timing right). Go into settings and disable pattern-lock.
However, I guess that might leave you without protection afterwards, as you need to verify with the old method before being able to reset it to a new. But still, I didn't try: it might as well be it ignores the "failed attempts" at this place. Phones: Use a hole to create a new account For phones there's a bad work-around according to this post: call the device from another phone (or have a friend calling it) answer the call, do not hang up use the back key (not the home key) over and over. This should eventually bring you to your home screen go to Settings → Google Accounts and add a new Google account. Sign in with this new account after it accepts the new account credentials, and logs you in, hang up the phone, and go back to the lock screen. Now, use the new Google Account's data to bypass the lock screen (via the "forgot" button).
example on Youtube