A person who seeks what they see by insistent solicitation and entreaty. Characterized by some presumption that they have a right to possess what they see even if it is yours. A grub will often consistently nag you if they really want what you got.
Sometimes the only defence to a grub is to
tell them to get the hell away from you and to get their own.
normal person: Hey check out my new
Mickey Mantle baseball card.
grub: Can I have that?
normal person: As if! You aren't serious are you?
grub: I thought you didn't need it.
normal person: Why?
grub: I thought you wanted me to have your baseball card.
normal person: What are you nuts? If I didn't need it I would sell it.
grub: No, I just thought you were being nice, besides c'mon what good is that card to you.
normal person: Just stay the hell away from me.
normal person: Get your own!