Facty is a human with short blond hair, rosy cheeks, grayish-black rectangular glasses, and brown eyes. They currently wear a blue T-shirt featuring the red text "Fact Attack Adventures" and a smiling, waving anthropomorphic lightbulb, as seen in "Folding a Shirt?" episode, along with red pants with a subtle dark gradient and green-and-white shoes. In earlier episodes, they wore a green T-shirt featuring an image of the ashwagandha plant and pink pants. Facty is a jolly, kind-hearted individual known for their immense curiosity and passion for learning, and enthusiastic about learning and sharing information with others. They are frequently accompanied by their close friends, Martian and LightBulb. In "Via Ferrata", they explain facts about the transportation system alongside their friends. They are also willing to learn new skills: in "How to Eat Spaghetti", Facty has difficulty using utensils but accepts LightBulb’s help. Facty enjoys going on adventures with Martian and LightBulb and is shown helping those in need, such as the Ashwagandha Kid. Facty is generally cheerful, kind, and friendly, and is shown to care deeply for their friends. In "Skate Park", they try to comfort Martian with words of encouragement. When Martian accidentally hurts them after the "Via Ferrata" episode, Facty does not appear to hold a grudge and continues to treat them kindly. Facty can become frustrated when someone takes something important to them, as shown in "How to Make Deviled Eggs", which may indicate they have anger issues. They are also portrayed as clumsy and have difficulty with some physical tasks. At times, they appear to have involuntary muscle spasms that cause them to punch objects.