|Relatives|| Adoptive brother: Kernel Fleck|
Adoptive father: Caspian Fleck
Adoptive mother: Melena Fleck
|Book Universe||The Demonata|
Art is a young child who was temporarily Kernel Fleck's adoptive brother.
When Kernel's parents first saw Art they were confused, knowing he wasn't their kid, so they kept and eye out for and missing baby reports. Meanwhile, the family moves to an out of the way place just in case people got too curious. When Mrs. Egin, the town witch, summoned Cadaver, he took Art and Kernel began to chase him along with the Disciples throughout the universes. Finally in Lord Loss' universe, Art was transformed back into Artery and joined in on beating down the Disciples for trespassing on Lord Loss' land. Artery was also put in the crystal chessboard, from Drust, to be a clue for Kernel, who had to guess the name of the demon thief. When he got it correct on the final try Lord Loss transformed Artery back into Art and offered him to Kernel to keep, but he also warned Kernel that as Artery aged, he would crave more human flesh and eventually turn on Kernel and his family as he would still always be a demon at heart. After some thought Kernel decided to leave Artery with Lord Loss.
An Old Creature took on the appearance of Art in front of Kernel.