One is a light blue Arabic numeral one (1), being based off the design of the "1" with a lower serif (𝟷), likely taken from the original Minesweeper. The upper and lower serifs of the "𝟷" are misaligned, the former more far off to the left. Unlike almost all well-known algebraliens, One doesn't have any arms. Got sealed in the moon for an accident which was the incident. prior to her isolation, One appears to be a nice but lonely person, eager to make friends with the other Algebraliens, eventually befriending Three. However, she also acts impulsively and doesn't realize what she's doing until it's too late. Trapped in the hollow moon that's somehow breathable, only dim, not pitch black, and remarkably soundproof. Does not require food nor water

Was absent when one got sealed in the moon. Doesn't know one is trapped. Two appears to be a green Arabic numeral two (2), with their green color being based off from the original Minesweeper. Two is drawn in the same style as Four and X, as they have limbs that are a lighter shade of green, being drawn simplistically and having four fingers. Two is a happy, carefree fellow in their own world that may come off as rude occasionally. They seem to appreciate nature and has never been known to do something evil, which is why the majority of One's power from the Yoylite found in 2009 was taken from Four and given to them. Two is shown to often leave, or act unbothered, when something negative happens. Does not require food nor water

Three is a light red Arabic numeral three (3) with limbs colored reddish-white. The exact proportions of her body is not always consistent from shot to shot. When she gets revived, her body and limbs become much more pale, with her color and left eye constantly shifting. Her body does not have a consistent border in this form, either, as it shifts erratically. Nice, but somewhat impulsive. Does not require food nor water

Four, as his name suggests, appears to be a blue Arabic numeral four (4), whose design is based on the version of "4" with an open top, most likely taken from the original Minesweeper. He is drawn simplistically and his limbs are more lightly-colored. Like most algebraliens, Four has four fingers. Four seems to be a fun-loving and friendly character, as he helps X discover his value. He also appears to be intelligent, since he is good at math. Four is also thoughtful, as after Three's murder by One, he publicly recognizes the dangers he feels One poses to society, and proceeds to organize & steward the ostracism of One from the number playground, including her exile inside the Moon. Does not require food nor water

X is a drawing of the letter X with a yellow body and lighter yellow limbs. Similar to Four, they are purposefully drawn simplistically, with different assets and four fingers. X appears to be a dependent and nervous but social Algebralien, needing help on finding his value. Not much in said by or about them in "Alone", but they hide behind Four as he took all the power from the Yoylite to try and fight off One for the time being. Nice. Does not require food nor water