A gnawler is a person that you wake up next to after a night of binge drinking. They are laying on your arm. You are so appalled by the person sleeping next to you that you would rather gnaw your arm off rather than taking a chance on waking them up.
I woke up with a gnawler this morning. I'm never gonna' drink that much again!
I thought my last blind date was ugly, but this one was a real gnawler!
You have never really been drunk until you wake up with a gnawler.