Kanegon's Cocoon (カネゴンの繭 Kanegon no Mayu) is the fifteenth episode of Ultra Q.
One day at a construction site, a group of children were finding valuables in the dirt when a man on a bulldozer ran over their bikes. When the children went to recover them, one of them named Kaneo Kaneda (in Japanese, kane means money) found a small object that had a jingle sound much like money in it. Later that night, the object grew into a magic cocoon that was releasing coins. However, when Kaneo went inside the cocoon, it started to swallow him up. That morning Kaneo woke up to find out that he had been transformed into an abomination. With everyone either being frightened or laughing at him, Kanegon could only rely on his friends to help him by giving him coins to eat. After hearing about his friends considering to take him to an old gypsy, Kanegon fled from the area and into the city where he started to eat some money from a bank that was being transported via suitcase. Somewhat dazed, Kanegon's friends helped him escape, only to be forced to do circus acts until he fell down. After unintentionally chasing the pair of bulldozer drivers from the day before, one nearly managed to run over Kanegon, but it fell from the edge of the hill. After the two bulldozer drivers were stuck in a hole, they desecrated the shrine of Kanegon's curse, launching him into the air and parachuting him back down. Upon landing Kanegon was turned back into a human. When going home, the boy found that his parents have also turned into Kanegons!
- Ultra Q Volume 4 features episodes 13-16, & Total Natural Color Blu-ray Volume 5 features episodes 15-17.
- In the big finale with the confrontation with Uncle Walrus, when Kanegon is ridding on the shovel/bucket of the bulldozer and gets shaken off, Kanegon's head falls off.