Sycophant: a person who acts obsequiously towards someone important in order to gain advantage
Bigot: a person who is intolerant towards those holding different opinions.
Proselyte: a person who has converted from one opinion, religion, or party to another.
Chauvinist: a person displaying aggressive or exaggerated patriotism.
Parasite: an organism which lives in or on another organism (its host) and benefits by deriving nutrients at the other's expense.
