How scary for you
However ... I really dont think you need to do more than teach Mason to bark and growl ... anything else and I believe you are asking for trouble.
In these daft times where burglars can sue the homeowner if they get hurt whilst in the process of robbing you , do you really want to risk your loved pet for some a-hole that he bites during a break-in
Most people would be deterred by a growling snarling dog anyway ... well if they had half an ounce of sense they would