A neck-lover or a vampire.
This person may be referred to as a "neck fetishist" or someone who has a specific attraction or preference for necks.
you call them bitefull
a traveller...
Pyromaniac.
geek
belligerent
sharp
a geologist
a traveller...
There is no special name for a person who likes squirrels.
Imaginative
a troublemaker?
How about a "gun enthusiast"?