I don't know why it took me so long but just now I finally understood the word pun in the donghua where Cheng Ke names the cat 小寸 in episode 3 at 13:35. I was really stumped for a long time about it. Since the Duo in Jiang Yu Duo is 夺, his nickname for himself is 大寸, therefore, his mini-me, the cat, is 小寸.
Original Work: 巫哲《解药》