The biggest asset that the Kardashian sisters share is their last name. And they absolutely do not want it to be co-opted by their brother's baby mother and wife-to-be -- currently known as Blac Chyna, seeking to become Angela Renee Kardashian. Surely having that name would boost her stock immeasurably, but Kim, Khloe, and Kourtney feel that Chyna taking their surname would do irreparable damage to the Kardashian brand they have worked so hard to build. 

According to documents obtained by TMZ, the Kardashian sisters feel that Chyna is "deliberately seeking to profit from the goodwill and popularity" of their family's brand. Indeed, that seems to be at least partially true, as in May it was reported that Chyna wanted to trademark the name of Angela Renee Kardashian in order to use it to represent her livelihood as a "social media celebrity." As she is set to wed Rob, one would think she could rightfully adopt the Kardashian name, though whether she is able to attain a "trademark" remains to be seen. 

Using all of their corporate strength, the Kardashian sisters are ready to battle Chyna's efforts to become a trademark-certified Kardashian, which they believe will cause them to "suffer damage including irreparable injury to their reputation and goodwill."

Last month, Chyna gave birth to her and Rob's first child, Dream Kardashian. The couple's "Rob & Chyna: Baby Special" premieres on Dec. 18 on the E! channel.