He's a vampire married to a vampire. 
Vampires are immortal unless killed with a wooden stake.
It's the Victorian era aka 1839 so not much technology. 
Vampires can not drink each other's blood!
Vampires can't go out in the sun
He has brown hair and red eyes 
he can hypnotize people, run fast, become a bat, and fly
aging, crotchety,has been through a lots. ruthless, cold, protective, caring, loving, strong, fast, smart. 
Morticia and gomez relationship 
Sleep during the day