We don't know why, but Herbie can't be hurt (unless it's funny). Bullets bounce off him, punches have no effect, he can't be executed, and he's not affected by fire. In many cases, Herbie is
unaware he has been attacked, and even when he is aware, you could not tell by his
expression.
Index terms: invulnerable, indestructible, impervious, immortal, fireproof, shatterproof, bulletproof, Richard E. Hughes, Ogden Whitney