A shapeshifter

Your father is doctor working on a cure for the common cold.

Because the cold germ constantly mutates even before a cure could be made it was no longer effective. So your father created a cure that mutated as fast as the virus.

With in a few hours your cold was gone. But the cure was not finished in you blood system and a month later you discovered you could change your face and body. Make yourself look like anybody you wanted to look like.

You could even make your tits bigger or smaller. Mare yourself thinner or fatter.

Suddenly you were the most popular girl in school.

Your pimples even quickly vanished.