Writer-director Seinfeld also stars in Unfrosted as Kellogg’s head of development Bob Cabana. He’s the (fully fictional) mind behind Kellogg’s hit cereal brands — who soon learns that the company’s rivals at Post have entered a new phase of the breakfast arms race.

Of the enormous cast joining him on this adventure, Seinfeld said: “It’s a huge cast. I don’t know how it got so big. I remember that we had nobody for a long time. And then Hugh Grant called and said he heard about the movie, and he wanted to be Tony the Tiger. Then, the next thing I knew, everybody was in it, and it was incredible.” So remember, if you’re ever casting a movie: Try to get Hugh Grant signed on as Tony the Tiger first.

Curb Your Enthusiasm, Bee Movie

Oscar nominee Melissa McCarthy takes on the role of Donna Stankowski, the wunderkind technician recruited to make Pop-Tarts a reality. 

“I loved how eccentric and how unwilling to compromise she is; that is always a character that I find interesting,” McCarthy told Netflix. “Stan’s a tough cookie. She’s smart and knows what she’s doing. Also, she is definitely in a male-dominated field in the ’60s, so she has to be someone who’s not afraid to stand up for herself.” 

Bridesmaids, Can You Ever Forgive Me?, The Little Mermaid, Spy, Ghostbusters (2016), Identity Thief, The Heat

Comedian and actor Jim Gaffigan plays Edsel Kellogg III, Bob’s boss and the money behind the Kellogg’s empire. 

“He is the CEO of Kellogg’s, which employs Jerry’s character, Bob,” Gaffigan told Netflix. “Together with Jerry and Melissa’s characters we pursue the creation of the Pop-Tart, and absurdity immediately ensues. My character is a bit of a buffoon who has inherited a lot of his status and his wealth, and he’s not really qualified for his position.”

Luca, My Boys, The Jim Gaffigan Show, Hotel Transylvania 3: Summer Vacation, Peter Pan & Wendy 

Schumer plays Kellogg’s corporate rival Marjorie Post, a real-life figure transposed into the madcap world of Unfrosted. 

“The real Marjorie Post was a really impressive woman who was one of the first female CEOs ever and built this incredible empire and did tons of good,” Schumer told Netflix. “I played a ridiculous version of her that has nothing to do with the real Marjorie Post. I’m sorry, Marjorie, but I had a blast playing fake you.”

Inside Amy Schumer, Trainwreck, The Humans, I Feel Pretty, Snatched, Sleepwalk with Me, Thank You for Your Service

Marjorie Post’s No. 2 man Rick Ludwin is played by New Girl favorite Greenfield.

“I’m sure she would describe me more like No. 30 or No. 0,” Greenfield told Netflix. “I’m there to help Ms. Post in this quest to find the Pop-Tart. My preparation for this role mainly was not to be too nervous on the first day around Jerry.”

New Girl; Veronica Mars; The Neighborhood; Promising Young Woman; The Big Short; They Came Together; Hello, My Name is Doris

In reality, Ravenscroft was an American actor who played Tony the Tiger for Kellogg’s. But Grant chose to play the thespian a little differently.

“The real Thurl Ravenscroft was American, and clearly I am not,” Grant told Netflix. “I play him as this bitter, unsuccessful British Shakespearean theatrical actor who is having to demean himself at this late stage in his career by being the voice of Tony the Tiger.”

Four Weddings and a Funeral, Notting Hill, Love Actually, Paddington 2, The Undoing, Bridget Jones’s Diary, Sense and Sensibility, About a Boy, Cloud Atlas

Enchanted star James Marsden plays Jack LaLanne, the late motivational speaker who (once again, fictionally) joins Kellogg’s effort to invent the Pop-Tart. 

The absurd pairing is part of the fun, according to Marsden. “It makes no sense whatsoever that Jack LaLanne, the fitness guru I play, is part of this endeavor between Kellogg’s and Post to create a boxed breakfast pastry,” Marsden told Netflix. “Jack is brought in as one of the taste pilots in Kellogg’s effort to hire popular TV personalities with big fan bases to put their minds to work to see how they can help invent a Pop-Tart.”  

Sonic the Hedgehog, X-Men, The Notebook, Westworld, Hairspray, Superman Returns, Hop, Zoolander, Jury Duty

Another addition to the Kellogg’s genius bar, von Braunhut is played by Thomas Lennon. In real life, the inventor originated the concept of sea monkeys; in the film, that invention quickly takes a demented turn.

“At a certain point in the film, a panel of geniuses is brought in to help crack the idea of the toasted breakfast pastry, and I play Harold Von Braunhut,” Lennon told Netflix. “He was a real-life, complicated historical figure who invented the idea of sea monkeys that he advertised in the back of magazines and you would get them in the mail. He became a multimillionaire from doing that.” 

Reno 911!, Memento, We’re the Millers, How to Lose a Guy in 10 Days, Weird: The Al Yankovic Story

Jack McBrayer plays Steve Schwinn, the bicycle scion who’s also been brought in to consult on the Pop-Tart.

“My character is Steve Schwinn, whose background is in bicycles,” McBrayer noted. “But Bob Cabana [Jerry Seinfeld’s character] wants to bring in experts in a bunch of different fields. So I bring in something that ends up being an inspiration for something that’s easy for kids to handle, like a Pop-Tart.” 

30 Rock, Late Night with Conan O’Brien, Wreck-It Ralph, Forgetting Sarah Marshall, Walk Hard: The Dewey Cox Story

Chef Boyardee: You know him, you love him, you probably don’t think the fictional pasta mascot is qualified to invent breakfast foods. Bob Cabana disagrees. 

Saturday Night Live; Mr. Mayor; Me, Myself & I; DuckTales; Star Wars Resistance

Famous son of Massachusetts Bill Burr takes on the role of another Bay State icon: John F. Kennedy. 

The King of Staten Island, The Mandalorian, The Heat, Daddy’s Home, Date Night, F Is for Family

Mike Diamond is a mysterious milkman who lurks on the periphery of Unfrosted. Does he represent the secret milkman mafia that allegedly lurks under the surface of polite society? Only time will tell. 

Heathers, Zoolander, Interview with the Vampire, The Name of the Rose, Robin Hood: Prince of Thieves, Broken Arrow