The highly anticipated Fox comedy "Grandfathered" starts tonight, and with a star-studded cast featuring John Stamos, Christina Milian and Josh Peck, it's nearly impossible to not have this on your must-watch list. While seeing Stamos as a grandfather is bound to be entertaining enough, Peck's hilarious personality and Milian's first break from reality TV in some time, the cast will keep you coming back for more.

It's hard to believe that Stamos is 52 years old — just look at him! — but the role of a bachelor-turned-grandfather is spot on for the single stud. Jimmy is a sexy bachelor who's been enjoying the single life for far too long, and finding out that he has not only a son, but a granddaughter all at once, is the perfect plot for the former "Full House" star, who believes the character hits "a little too close to home." "It's a little scary," he told Entertainment Weekly of their similarities. "I was watching the pilot the other day and was like, 'Am I watching a pilot or is this an 'E! True Hollywood Story?'"

After taking a break from starring TV roles for a while, Stamos couldn't be more excited to be back on the small screen. "Everybody loves it," he explained. "I hope everyone can feel how much fun we're having. Magic has to happen — chemistry, the right people, the stars have to all line up for something to be a hit. This show feels like that more than anything I've had since 'Full House.'"

Creator Danny Chun also couldn't be more pleased with his casting choice. "He's just at such an interesting moment," Chun told Variety about Stamos. "It's really just a perfect moment in his career for a role like this. I think he's just really positioned for something amazing. He's an amazing actor and great to work with. He's every writer's dream collaborate as a star, in terms of his talent and temperament. He's a TV star in a way that very few people are. The connection that people feel with him, that's exactly what a TV star needs to be."

As for Peck's character, Jimmy's son Gerald, we're bound to see more of the guy we know and love from his early acting days on the hit Nickelodeon show "Drake & Josh." The former child star is all grown up and ready to take on his first big role, and it looks like he'll have the ladies swooning. "He's tall, dark and handsome, but he doesn't know it," said MTV in its perfect description of Peck. "Instead, he looks like 'walking birth control.' He's awkward and a bit of an idiot, but Peck's earnest performance totally sells it." Peck, 28, is also a major Vine star, with 6-second videos that will have you laughing for days.

While Stamos and Peck may seem like total opposites, they love working together and got along in a way they never could have imagined. "I learn a ton from Josh," Stamos told People. "He's a really good man. He's a gentleman and knows himself. He's got a cool sense of humor, which is different from mine. Even the first day of shooting, I was like, 'How would you say this? Give me a joke here.' He's a smart, sharp guy."

Milian, on the other hand, is mostly known as a singer. Most recently, she's been featured on a few different reality TV shows, including "The Voice," "Dancing With the Stars" and her own show, "Christina Milian Turned Up," so she was excited to switch things up a bit. In "Grandfathered," the 34-year-old plays Vanessa, the mother of Gerald's daughter and Jimmy's granddaughter. Milian was excited and determined to take on this role as she doesn't "want to become just a reality star." "I'm sure there are other people who have done acting and reality at the same time," she explained to the Huffington Post. "If they haven't, then I guess I would be the first. I would like to be able to prove that it can be done." The second she read the script, she knew she could "relate to this character."

Vanessa and Gerald had a one night stand that, obviously, ended in a pregnancy, and while they remain good friends, things do sometimes get complicated between the two. "There's all these fun elements of Gerald still liking me and wanting to be together with me," said Milian of Vanessa. "And me being like, 'Oh gosh, I got a lot of stuff going on and I'm not really into you.'"

The baby, Edie, may be the cutest thing about "Grandfathered," and all the stars absolutely loved working with the twins, Layla and Emilia Golfieri, who play her. "They're beautiful, they're adorable and they're difficult," said Stamos of working with kids. "In the pilot, I knew I had to get that scene where she kissed me, but they screamed and bawled the entire time. It was like I was sticking needles into the poor kid! Eventually the comedy gods were smiling down on me and she did it."

"The way I love my [on-screen] daughter, I'm kissing her and I'm hugging her and I'm very affectionate with her," said Milian of comparing her role to how she loves her own daughter, Violet. "I don't want it to feel cold. I want it to feel like it's my baby. As a mom, I know how you are when it's your child compared to maybe your friend's kids — it's different."