Charli XCX -- Good Genes or Good Docs?!

Charli XCX's looks over the years are so BRATTY!

Here is a 21-year-old version of the singer-songwriter, "fancy" in leather, at the mtvU Woodie Awards and Festival in Texas back in 2014 (left). This was the same year she collabed with Iggy Azalea on "Fancy" and dropped her hit song "Boom Clap."

And a decade later, Charli recently stayed true to her fierce leather roots -- making a visit to "The Howard Stern Show" (right) and discussed all things "Brat Remix" -- her new album which dropped earlier this week.

How do you like them apples?!

The real question here is: