His design heavily incorporates cloud elements into his white wool, giving him a soft, dreamlike appearance that complements his perpetually tired and sleepy personality. He is characterized by blue, sleepy eyes, large lavender cheeks, and a dark face that contrasts with his bright wool. Nimbus's attire is centered around a sleep theme; he wears an oversized blue sweater that hides his arms, a blue and white striped scarf, and a long blue nightcap adorned with a jingle bell at the tip. Additionally, a baby blue sleeping mask featuring a closed-eye design often rests on his wool. Nimbus is characterized as a caring and kind-hearted individual who often appears sleepy or tired. Despite his constant state of exhaustion, he is noted for having difficulty actually falling asleep, a struggle reflected in his design as a fluffy sheep with cloud-like wool and sleepwear.