Astro is a light aqua Toon with his face resembling a waning crescent moon. The right side of his face is pitch-black with a white star-shaped eye. He wears a cornflower blanket wrapped around his torso, obscuring his four arms to the point that they can be just seen as faint furrows in the blanket. However, his blanket is still short enough that it reveals his legs that are the same color as the crescent moon side of his face. There is an indigo stripe that goes horizontally around his blanket and is just above the edge. Underneath his blanket, he wears medium black shorts that are barely visible due to the blanket covering them, but previous versions of him never had the shorts. He wears a dangling sleeping cap the same color as the stripe on his blanket, with a light blue trim and a light blue pom-pom at the tip. During Blackouts, he emits a blue glow. Astro is an introverted, shy, and calm Toon who likes to interact with his fellow Toons, albeit without leading conversations. He enjoys peace and quiet and could get agitated or standoffish when disturbed, but has really only lost it with Connie 's behavior and nobody else's. He speaks formally but has a playful, humorous side, despite appearing not to, suggesting that Rodger tries to find more hobbies in a mocking tone, and laughing whenever Waxwell repeatedly yells about giving people nightmares. He's open to helping his friends with their issues, especially their dreams, but sometimes tries to turn down help offered to him, preferring to be the one lending a helping hand or four. But he does easily doubt some of them, yet remains calm as ever when he does so. Repeatedly talking about something or worrying for him can irritate Astro, and he finds it odd. Toons like Looey are why his skepticism sometimes goes too far, and he needs to double check his thoughts and not be overreliant on his own mind.