A cuddler. Someone you can cuddle -- *
snuggle* -- with. Usually someone you
know well, and where the relationship dynamic is such that there isn't (
too much) sexual tension.
She's my snugglebunny for after
scary movies when I can't sleep.
We both had recent breakups, and
decided we were both cuddle-deficient, so we
decided to be snugglebunnies for a night.