Klonoa's general appearance is very simple. He has primarily black fur, with his snout, hands, feet and the ends of his long ears being white. His eyes are golden-yellow with slitted pupils. He also has long, fluffy ears with the ends resembling maple leaves.

In Klonoa: Door to Phantomile, Klonoa was much more feline in appearance, with large, yellow eyes that resembled real cat-like eyes with very little, if any sclera showing and noticeable fangs. His attire consisted of red shorts, a teal green belt, a light blue Pac-Man cap, yellow gloves, a large oversized red dog collar that was worn around his neck and brown and white shoes. He also went around shirtless.

In Klonoa: Moonlight Museum, Klonoa's appearance was changed slightly; his eyes were given a more traditional animated look as well as making him somewhat taller, his belt is now brown instead of teal green, and his oversized red dog collar now lacks details.

In Klonoa 2: Lunatea's Veil, he went through a significant design change. Klonoa now wears a blue high collared t-shirt with a large zipper pin, dark blue high waisted shorts with yellow buttons on the sides, a backwards blue cap and red and white hi-top lace-up sneakers with white soles and white shoelaces. He also still wears yellow gloves. His face was altered a bit as well, giving more focus to the fur around his mouth, as well as making his eyes narrower while still retaining his cat-like pupils and yellow colourization. This is the appearance he would keep through future games, with the sole exception being the Klonoa Wii remake.

In Klonoa: Dream Traveller of Noctis Sol, Klonoa looks older and now wears a red t-shirt similar to his usual blue t-shirt, but with a new blue Pac-Man cap, a large, slightly oversized red collar on his neck, blue shorts, red and white hi-top sneakers, a red belt, and yellow gloves. He was also given a wider body and larger irises. The comic shows his sleeping attire, which is striped pyjamas that consist of light blue for his pyjama pants and cyan for his pajama shirt.

In the Wii remake of the first game, his attire has, once again, been altered. He now wears a short-sleeved red open jacket with a yellow collar and pale blue sleeve ends, a darker blue Pac-Man cap, red calf-length shorts with a black belt, yellow gloves and brown and white hi-top boots. Much like his Door to Phantomile appearance, he also doesn't wear anything underneath his short-sleeved red jacket. His irises also appear two-toned (half yellow, half orange).

His design in the cancelled film remains the same as his Dream Traveller of Noctis Sol design, except for the fact that his t-shirt is replaced by a yellow trench coat.