A person who needs constant attention. To "thirst" on a regular basis; day by day thirst. When the "thirst" goes above and beyond.
Me: Oh man I cant wait to go see Joe tonight, he is taking me out to dinner and a movie.
Cousin: Ooo I can I come? If I cant come can I get a doggie bag? Tell Joe I said "Hai.."
Me: Nah thirst monster.