(at least he has the colors of a doberman)....
He said he wanted a doberman to protect us from intruders, but our little 4 month old Buddy is already a fantastic watchdog. He hardly ever barks unless he hears a strange noise--especially the sound of a voice he doesn't recognize or a strange noise at night. He might not be able to fight an intruder, but he can be a little "alarm" to wake up my husband (who with his various weapons and military skills is more than able to take over).
I never thought of a Chihuahua as a guard dog, but he really is great at it.