chew off
To separate something from something else by biting or gnawing. A noun or pronoun can be used between "'chew" and "off." Our new puppy is lucky he's so adorable, because he's already chewed the leg off our nightstand.
chew something off something
and chew something offto bite or gnaw something off something. The puppy chewed the heel off my shoe. The puppy chewed off the heel and mangled the tongue.