- Tyrone Savage as Nicholas Morgan
- Janet-Laine Green as Martha Morgan
- Booth Savage as Tom Morgan
- Alicia Panetta as Sam
- Angelo Mosca as Cadaverous Man
- Julissa Aguirre as Grace (voice)
- Deanna Oliver as Chloe (voice)
Differences from the story
- In the story, the monster baby's name is Hannah. In the episode, her name is Grace. In the story, the name of the baby at the end was Grace. In the episode, it's Chloe.
- In the story, Mick reads a comic book featuring a villain with a "mark of evil". He sees that the baby has the same mark and starts getting worried. This is not in the episode, so he doesn't freak out until the baby acts weird.
- In the story, Nicholas doesn't like the idea of having a baby sister. In the episode, he is excited about it.
- The episode adds a female friend character.
- In the story, the baby's real family was just one parent, a human looking mother with the same birthmark as her. In the episode, she has a mom and dad, who appear to look like monsters.
- The story doesn't give Nicholas' last name but the episode reveals it to be Morgan. This was the last name of his sitter in the story, who is not in the episode.
- The story shows Nicholas' parents getting a call that informs them they have the wrong baby, and reacting badly to it while Nicholas is visibly happy. The episode just cuts to them telling this to Nicholas, on the same day that the real parents come to get the baby and they apologize for doubting him.
- At the end of the story, Nicholas tickles his baby sister, only for her to threaten him. He runs away screaming, as she continues her threats. In the episode, he is talking to her in a baby voice, and she tells him to cut it out and to feed her, in which he rolls his head and sighs, aghast that it's still not over.
- Tyrone Savage (Nicholas) played Daniel in season one's, "It Came from Beneath the Sink".
- Booth Savage and Janet-Laine Green, who played Nicholas' parents, not only were a real-life couple at that time, but they were the real-life parents of Tyrone Savage, who played their son.
- The toy block that Sam picks up from Grace's crib bears the Goosebumps "G" logo.
- When Nicholas is fighting with the baby for the remote, the channel is switched and a scene from a previous episode, "Say Cheese and Die" is shown. Ironically, the next episode after Strained Peas was its sequel, "Say Cheese and Die - Again!"
- This is the lowest rated Goosebumps episode on IMDb, with a score of 3.7/10.
- In one scene, Sam leaves Nicholas's house with a skateboard with the cover design of The Haunted Mask. The skateboard is the same prop as seen in Grady's room from The Werewolf of Fever Swamp episode.