Art, by his name, loves art. He was born in a family of commoners that owns an art studio, sometimes helping wealthy families to draw paintings, etc. He joined the knights in hope for some exciting events, and a bit of respect, since you don't get a lot as a commoner. But one thing he hates is the thing about his habit of eating flowers, since it's the only way he could refill the poisonous paint-like substance from his tail. Art thinks that's a herbivore-like act, to constantly munch on flowers. In his free time, he draws on...Everywhere with his paint, but once the substance dries up, it's not toxic anymore, but it'll glow in the dark- in which he got the idea of painting battle-markings on himself, making Art look like a neon glowing Wilak in the night, sometimes making enemies mistake him as an idiot rather than what he wanted to be a magnificent beast.
By the way, as noted, the color of the flowes he eats will be the color of the paint, so Art tries his best not to eat pink flowers, since it'll just make him look ridiculous rather than scary. Also, he is quite small for his age, allowing him more agility and speed rather than strength. Plus. his tail is constantly dripping paint, and his eyes also glows in the dark. (Ps. He constantly carries a sidebag full of colorful flowers, for when he travels far from his sector)