With her striking, ever-changing hair color and grungy style, one could easily assume a lot of things about singer Billie Eilish. But you know what they say, never judge a book by its cover.

See what really makes the star singer so popular among her growing fanbase, which even includes rapper Cardi B and rocker Billie Joe Armstrong! Watch the video above!

Surprising facts about singer Billie Eilish 

Billie Eilish performs on stage during KROQ Absolut Almost Acoustic Christmas, California, 2018