Rob Kardashian
Rob Kardashian, photographed at the opening of Kardashian Khaos in Las Vegas on Dec. 15, 2011, took to Instagram to share a few cryptic posts while his family celebrated Kylie Jenner's 18th birthday. Getty Images

Rob Kardashian has resurfaced on Instagram once more with some very odd posts. The Arthur George founder has been withdrawn from both the public eye and all forms of social media for the majority of the last few years. Though he doesn't post often, Kardashian, 28, will occasionally break his social media silence with a brief Twitter message or Instagram post, much like those posted to his account on Sunday.

While the rest of the Kardashian clan gathered at The Nice Guy in West Hollywood to celebrate Kylie Jenner's 18th birthday, it appears Rob opted to stay home. According to Us Weekly, as his sisters were flooding followers Instagram feeds with photos from the celebration, he decided to get in on the fun in his own way. Rob uploaded a photo of what appears to be a bottle of Paul Newman salad dressing with the caption, "RIP." The photo showed a close up of the label featuring a cartoon version of Newman and the words, "All Profits To Charity." An hour later her shared a still from the movie "Miami Vice," which depicted Colin Farrell and Li Gong riding in a speedboat together. He captioned that photo, "MOOD!"

Rob only recently returned to Instagram after deleting all his photos and taking a lengthy hiatus. His first post following the clearing of his feed was a shirtless throwback photo. The photo showed Rob sitting on a beach in Miami eating a sandwich. It is unclear when exactly the photo is from, but it appears to have been taken prior to his weight gain.

Unfortunately for Rob, his attempts to garner attention from his siblings were futile. Kim Kardashian, Khloé Kardashian and Kourtney Kardashian were too busy partying the night away to take notice. The following day each of the Kardashian sisters, along with Kylie Jenner, Caitlyn Jenner and Kris Jenner, took to Twitter and Instagram to wish Kylie a very happy birthday, ignoring Rob's outburst completely.

Kylie, her famous family and close friends celebrated her big day with a major blowout at Bootsy Bellows. As we previously reported, during the party she was surprised by rumored boyfriend Tyga with a brand new Ferrari. According to E! News, the car is thought to be worth around $240,000. Prior to that it was rumored Tyga, 25, had gifted her a brand new Mercedes G-Wagon. At the time it was believed that the car had once belonged to Blac Chyna and had simply been repainted before being regifted to the youngest of the Jenner siblings.