Mrwhydden (pronounced MUHR-whih-den) is a powerful sorcerer who first made enemies with Abin Sur, Hal Jordan’s predecessor as Green Lantern 2814. In order to cast his spells, Mrwhydden has to speak them in rhyme or else they will not work. Abin takes advantage of this by gagging the sorcerer's mouth with his ring, keeping Mrwhydden from saying anything at all. Abin imprisons Mrwhydden by shrinking him down to microscopic size and trapping him inside a realm witihin his power ring. Although beaten, this would not be the last time Mrwhydden would plague the Green Lanterns.
Many years after Abin Sur's death, Mrwhydden finds that his powers have returned, although he is still unable to leave his prison within the ring. To make himself known to Abin's successor as Green Lantern, he uses his magic to create a construct of Abin Sur to fight Hal, but Hal beats the construct in battle. After the fight with the fake Abin, Hal asks his ring about Mrwhydden. The ring informs him of Mrwhydden's battle with Abin and that the spell caster is currently being held in a miniature realm within Hal's ring. The first encounter between Hal and Mrwhydden seems to show Hal completely stripped of his powers. Soon though, to Mrwhydden surprise, Hal seems to develop the ability to use magic himself. To remedy this problem, Mrwhydden cast a spell that removes all magic, including his, from the micro-realm. Predicting this, Hal then reveals that his newly acquired "magic" is actually just his old power ring abilities. Since he is inside his own ring, he is still able to manipulate the green light and did so to imitate magic. Hal then proceeds to remove the ability to speak from Mrwhydden, keeping the magician from casting spells and trapping him again.