He appears in one of the mini-games in the DS version.
"The Night Patty"
Nosferatu hides in the cooler during the night shift and is the boss there. He approves SpongeBob to be a fry cook for the night shift by drinking his blood with a straw.
Contrary to popular opinion, the word 'nosferatu' does not mean 'vampire','undead', or anything else like that. The term originally came from the old Slavonic word 'nosufur-atu', which itself was derived from the Greek 'nosophoros'. 'Nosophoros', in the original Greek, stands for 'plague carrier'.