Rob Kardashian weight loss pics show the star's epic transformation

As Khloe Kardashian turned 36, and her family chimed in to celebrate the Keeping Up With The Kardashians star's birthday, it was brother Rob who stole the show.

Rob Kardashian who is the youngest of the Kardashian siblings has been battling some weight issues off late. However, the 33-year-old surprised his Instagram followers with his latest transformation pictures. Mom and celebrity manager, Kris Jenner and Rob both posted pictures from the party.

Kris Jenner posted the snap of the siblings, Khloe, Kendall, and Kylie with Rob with a caption, "4 out of 6 #happybirthdaykhloe." Kris posted another picture of the siblings, Kourtney and Rob with a caption, "These two cuties @kourtneykardash @robkardashianofficial #robkardashian #happybirthdaykhloe."

Rob wore black trousers and a matching black hoodie. He chose to complete his look with his statement blue cap. He looked many pounds lighter and fans were quick to appreciate his weight loss efforts. Many comments flowed in like, "Rob is Back best thing on 2020", "Yesss rob! good to see you so happy ", "Rob!!!! So freaking handsome!", and "You're looking great ."

Rob also posted pictures with Scott Disick, 37, Kourtney's ex-husband with a caption, "Appreciate it ". Tristian Thompson 29, who is Khloe's ex also appeared in a picture with a caption, "Woo back baby".

Khloe had earlier revealed to ET that Rob had been working out. She said, "He goes to Kim's, he's worked out for, like, the past five days or so, and he's kicking a**, and I just want Rob to do what's best for him and what makes him happy. "And if that makes him happy, then we will all support him."

While the entire Kardashian and Jenner family was present at the party along with some of their exes, Kim Kardashian West, Kanye West, and their children were not seen in any pictures.