Uncle Time is Father Time's brother, the deity in charge of Timeless Space. He is also the pet store owner who sold Bun-bun to Torg [1]. It was he who returned Bun-bun to his original timeline after both of Bun-bun's trips into Timeless Space, Bun-bun having "solved the riddle of Uncle Time". (Actually, Bun-bun had never even heard of the riddle, and it is in fact never stated, though the answer appears to be diving into the Oceans Unmoving.)