Kim Kardashian's particular brand of fame has become so ambiguous -- "fashion design," Khroma Beauty, motherhood, her relationship with Kanye West, a shot at acting here and there -- that we'd almost forgotten what landed her all those opportunities in the first place. You can say what you want about Kim, but there's no denying that she's done pretty well for herself for a girl who got first got her name in headlines just by being Paris Hilton's friend with the big butt.

For the most part, these days we're more prone to recognizing Kim for her beauty and fashion approaches than for the body part that made her a star, but every once in a while she has no problem reminding us of her assets. To wit: this friendly butt contest (are they competing?) between Kim and her gal pal Chyna Blac, which the ladies documented on Instagram, as you do.

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We'd venture to say that they've both got more than ample junk in the trunk, and it's looking pretty good... which reminds us, we should really be following through on those New Years resolutions to hit the gym. Kim is nothing if not an inspiration to keep pushing through with those squats. [Instagram]