- "I swear I made PAMA with good intentions. It was designed to automate things. Make everything more efficient. Use monsters to help with farming or mining."
- —Harper explaining why she made PAMA.
Harper is an inventor who wears a yellow jumpsuit outfit with a brown hoodie, black goggles, green eyeshadow, black gloves and black shoes. She also has white hair, black eyes, gray eyebrows, and dark skin. Also revealed by a painting, Harper used to have black hair and black eyebrows around the time she created PAMA.
Harper is portrayed to be an intelligent individual with a brave and resilient personality. At first, she appears apprehensive and unfriendly. However, as the story progresses, she proves herself to be both loyal and caring towards Jesse's Gang. She is also a great inventor and is responsible for inventing PAMA and the Mind-Control Headset, but appears to suffer from loneliness as a result of her isolation. As a result, she created several robotic greeters named after Crown Mesa's citizens to help her cope with this.
She programmed the robotic greeters so they can tell her to forgive herself, showing that she blames herself for all the trouble PAMA has caused. While apprehensive about befriending others, she is also very loyal to those she does befriend, such as Jesse's gang, to the point in which she is willing to stand up to Hadrian at one point. Harper also has a habit of eavesdropping on other people's conversations.
- Poppy (Formerly)
- Water Bucket
- Mind-Control Headset (Formerly)
- Enchanted Diamond Pickaxe
- "Nice work, new guys! But I'd get outta there fast if I were you - PAMA's a quicker learner than you think!"
- —Harper to Jesse and Ivor. src
- "So tired of being carried away while I'm trying to explain things!"
- —Harper being carried away from the mind controlled mobs and citizens into PAMA's core. src
- "We need to get to my secret lab."
- —Harper to Jesse's gang. src
- "Make sure you don't drool on my floor now."
- —Harper to Ivor. src
- "You are a strange, strange man Ivor. But you know something? You're OK."
- —Harper to Ivor. (Determinant) src
- "Before you go in there, I have one piece of advice: don't die!"
- —Harper to Jesse's Gang. src
- "Now you two take care of each other, all right?"
- —Harper to Jesse and Ivor. (Determinant) src
- "I appreciate the vote of confidence, Jesse. Sorry, I couldn't resist a good eavesdrop. I promise I'm trying to help, Lukas."
- —Harper to Jesse and Lukas. (Determinant) src
- Harper is the second person to have created a major antagonist in the series (PAMA) after Ivor created the Wither Storm.
- However, her creation turned against her by will rather than its creator's command.
- When Jesse is wearing the Mind-Control Headset, they can see the text "HARPER v 188.8.131.52" on-screen.
- As a member of the Old Builders, she is known to have helped create The Portal Network.
- As shown in a painting of her and a young PAMA, Harper used to have black hair. This also suggests that either Harper created PAMA long before the events of the game, or her hair grew white from stress caused by PAMA's betrayal.
- Its also a reference to Steve Jobs and his iconic pose with the macintosh.
- Harper also seems like the Old Builders' counterpart to Ellegaard the Redstone Engineer.
- At the end of Episode 8, Harper said that she would try to help the townspeople of Crown Mesa rebuild, saying that even though that was not her original home, it was the closest thing she had. This suggests that Harper came from another world. Earlier on in the episode, Harper mentions that she was from the Old Builder's World.
- She is the only Old Builder to appear in more than one episode.
- Harper and Otto are the only known Old Builders who are not corrupted.
- Harper's final fate in Episode 8 depends on whether or not Jesse defends her from the citizens of Crown Mesa in Episode 7.
- If Jesse does, they will supposedly accept Harper back into their community, and after Jesse gets the Portal Atlas and can find their way home, Harper will return to Crown Mesa and help her old friends recover from PAMA.
- If Jesse doesn't defend Harper, the citizens of Crown Mesa will reject her and, after Jesse gets the Atlas, Harper will either find a new homeworld or help Otto fix the Builder Games. Jesse can suggest that she come with them (The New Order of the Stone), but while she appreciates the offer, she will reject it, as she feels she can't keep tacking herself on to other people's lives.
- One of Harper's quotes is, "...and I'll make this world great again!", which is a reference to Donald Trump's quote, "I'll make America great again!"