Role in the film
Peter is first seen with his mother holding him as she comes to the door to welcome Wolfe. Julie puts him down after she introduces him to the other kids, Zoe and Seth. He is later seen holding Seth's hand and his own hand in his mouth as Julie kisses him goodbye. He is seen again standing in the fish tank and throwing Cheerios all over the place, until Helga mutters, "Thank you, Peter", after he throws Cheerios on her face, which upsets Tyler. He is briefly seen in bed while Helga sings the "Peter Panda Dance" for him.
Peter is seen the next morning at the table at breakfast, and when Lulu finishes copying Wolfe, he farts. He is seen again in the bathroom playing at being a ghost with a blanket on his head, which annoys Lulu. Wolfe comes in, telling Peter to stop, and places him on the toilet, and Peter shakes his head "no" when Wolfe tells him if he has seen the ghost that Lulu was talking about. He is seen again with his siblings and in Seth's arms and farts.
He is seen the next morning, between Tyler's cries, he pulls the tablecloth off the table and is seen again in the toddler carrier, his booster seat, at school and at the supermarket where the Fireflies, Lulu's troop, hold a cookie stand. Later, Wolfe realises that he has left Peter at Woody Woodchucks and turns back to get him, but Wolfe pulls him bare-naked out of the ballpool.
Peter is briefly seen standing in the car watching Zoe drive. Then, that night, Seth tells Wolfe to do the Panda Dance to stop him crying, and writes the lyrics down for him. Wolfe tucks Peter in and gives the dance a go. He is seen again in his room, after Wolfe puts Tyler to bed, he does the Panda Dance for him, properly like he practised. After the dance, he says goodnight to Peter and Peter replies, "Goodnight, Daddy". Wolfe doesn't think he is Peter's real father, but he says goodnight to him. He briefly appears in the supermarket when Wolfe sees the Fireflies beating the Bear Troop.
He is later seen when Zoe and Seth bring Peter and Tyler to their room when two burglars break in. Then they come out and desperately hug Wolfe. Peter reappears when the children welcome their mother home. Later, Mr. Chun has Peter and Tyler in the playpen and Seth, Zoe and Lulu tied up together on the floor, but when Zoe says, "Now, Peter!", Peter squirts juice in Mr. Chun's face.