A particularly dangerous type of femme fatale
who uses cuteness to lure her prey.
Outside, she'll look like a defensless, innocuous innocent girl, but actually a see-kay is pure evil and can crush you with a finger.
1: I had no clue that I was with a see-kay, until she grawled and scared the sh*t out of me.
2: He fell in love with a see-kay. There's no hope of saving him anymore.
3: A see-kay is like a cute little furry rodent: it bites.
4: See that scar-covered convict there? He tried to mug a cute little girl in a dark alley, turned out to be a see-kay.