We're already fans of body positivity activist Whitney Thore, the star of TLC's My Big Fat Fabulous Life, but now her friend Mattie has found a way into our hearts! Here's everything we learned about the hilarious member of Whitney’s Big Girl Dance Class — who's quickly becoming a favorite on the show.

She serves all the sass on My Big Fat Fabulous Life.

From threatening to burn rival dance instructor Jiya’s “synthetic weave” to catching an attitude with guest choreographer Jenzi, Mattie made a name for herself as the queen of clapbacks.

She underwent a weight loss transformation.

Mattie — full name Mattie Bynum — posted this before-and-after photo of her progress. Looking great, girl!

MORE: 'My Big Fat Fabulous Life' Disease — Find out What Caused Whitney Thore's Weight Gain

She’s a fabulous hairdresser.

She always makes her customers look good, and even styled Whitney Thore for a fashion show in a previous season of My Big Fat Fabulous Life.

MORE: 'My Big Fat Fabulous Life' Star Whitney Thore Twerks on Instagram — See Her Dancing With Mom Babs!

She's a supporter of Whitney’s body positivity campaign.

When she’s not shaking her booty in Whitney’s Big Girl Dance Class, she’s sharing sexy selfies — and she’s not afraid to show off her curves with the hashtag “#NoBS.”

Scroll through the gallery below to see photos of Whitney proudly showing off her body on Instagram!