The Shadowhog rules over a dimension of pigs. He has the power to change peoples taste buds so that all they taste is pork. He is about 8'6" tall according to Gaz, and enjoys ballet, tea, video games, and tormenting souls. His first and only appearance is in the episode Gaz, Taster of Pork.
Dib summoned the Shadowhog to test his powers on Gaz, which made everything but actual pork products taste "like a pig". After receiving some help from the Swollen Eyeball Network, Dib was able to pull them both into the Shadowhog's dimension.
The Shadowhog had Gaz go through two trials, both of which she handled with ease, thus freeing her from his curse. Despite planning to set both children home free, he Shadowhog sentences Dib to cleaning his toilet with a brush attached to his head, due to Dib begging him to "punish [him] instead".