Referring or describing to a really hot/sexy young girl/teenager/tween (high school cheerleader, hs volleyballah, Selena Gomez) but due to extracurricular activities; one who just woke up; no makeup on, that looks like shit.
-"Damnn did you see Selena Gomez w/o makeup on Variety? She looked like a thunderkitten!"
-"Dude, your lil sister looks like a thunderkitten."
-"No matter how much makeup she can put on herself, Miley Cyrus will ALWAYS look; be a thunderkitten."