A man or woman who has extraneous amounts of beach related elements, plants, or toys stuck on his or her face or hair. Usually this person will consider this fine and normal.
Kara's hair is full of sand, and even a fricken lobster, and she doesn't even care. She's such a beach head.
Its when a man is getting a blow job and his partner has a pepper in their mouth forcing the pepper and seeds of pepper into the hole and sucking them back out to end the Wet Back Head.
Man, i woke up this morning and my dick was on fire. Must have been that wet back head i got last night.