He is a Viking biker who obtained a can full of dangerous chemicals and used it to become all-powerful. With an army of killer vegetables and Helling Guards, he invaded the land.
Ed, who accidentally dropped the can down the trapdoor of a ship onto the planet, set out to defeat Grögh and get the can back from him. After collecting enough items from the different areas invaded by Grögh's forces, Ed was able to go to Grögh's Kingdom.
There, Ed came face to face with Grögh, who was driving a fearsome robot his followers built for him. Grögh chased Link to a room full of Lava, where Ed turned into Super Ed and knocked the robot into a hole. Ed jumped down the hole after him to battle with him for the final time, eventually defeating the robot with his Peashooter. Afterward, Ed entered the robot and whacked Grögh on the head with his stick. Grögh complained that due to the Pharmacist's groga plans and genetic malarkey nothing was much fun anymore, and threw the can to the ground before exploding in a puff of smoke.
- In the N64 version of the game, after Grögh is defeated and says his final speech, he says "And then that damned pharmacist came along..." A different version of the game changes "damned" to "darn", though retaining the line "It feels like I've been to hell and back."