Woody first sees them after getting played by Bonnie. After Bonnie flips over her toy basket and leaves to make a "spaceship", Woody backs away and bumps into the peapod. It unzips itself to reveal three plush peas named Peatey, Peanelope, and Peatrice. Peatrice asks who he is before Peanelope timidly asks if he's a real cowboy. Woody is about to answer before Peatey interrupts and calls Peanelope a "Pea-Brain" for believing he's a real cowboy since he doesn't even have a cowboy hat. Woody is about to correct him before he realizes he's lost his hat. Suddenly, Bonnie returns and they all go limb as the little girl puts them is her homemade spaceship.
The night, Bonnie's toys all sleep with Bonnie in her bed when Woody quietly sneaks off to find Bonnie's backpack with an address on it. The others quickly wake up and ask him what he's doing. Woody explains that he has another kid named Andy who's leaving for college and that he needs to get home. Peatey asks Woody where is his home, to which Woody states Andy's address (234 Elm Street). After Woody asks for a map, the toys lead him to Mrs. Anderson's computer. Later, after informing them that he escaped from Sunnyside, Woody listens to Chuckle's story that Lotso rules Sunnyside with an iron fist and is keeping Andy's toys imprisoned. Woody soon leaves to rescue them.
At the end of the film, Andy soon arrives at the Anderson's home and donates his toys to Bonnie. The two then play together with both of their toys for the rest of the afternoon. The gang then watch from Bonnie's porch as Andy slowly drives away.
In the end credits, the Potato Heads are watching Totoro juggle the Aliens when Mr. Potato Head's parts begin to pop out of their holes. Suddenly, there's giggling coming from Mr. Potato Head's pouch. The three peas (now out of their pod) open his pouch and begin to bounce away laughing. An angry Mr. Potato Head then warns them to "stay out of his butt!"
The Peas-in-a-Pod briefly appear when Woody announces that Bonnie has gone on vacation for winter break. Later, they are seen sitting by the door when Peatrice tells everyone Bonnie is coming.
They make a brief cameo as a drawing on Bonnie's wall.
The Peas-in-a-Pod only make a small appearance during the sequence of "You've Got a Friend in Me", where they are carried in a colander with other toys by Bonnie. They also make another cameo as a drawing on Bonnie's wall. It can be assumed they were in another part of the house or stored away, as they are seen in Forky Asks a Question.
Despite their small cameo in the fourth installment, the peas are set to appear in the upcoming series, dancing with Forky as he learns about cheese.
The Peas-in-a-Pod make their appearance with the rest of Bonnie's toys as they are around a game board set up by Hamm to tell them about the journey in the third film.
- Peas-in-a-Pod are based on one of the Vegimals, stuffed toys resembling fruits and vegetables with faces, produced by Freemountain Toys in the late 1970s.
- The only Toy Story Toons episode they haven't appeared in is Small Fry.
- It's unknown why the Peas-in-a-Pod didn't have a major role in Toy Story 4, presumably because they didn't serve any purpose to the story. But they later appear in the Disney+ series, Forky Asks a Question.