From Muppet Wiki

Morris Fraggle was a background Fraggle on Fraggle Rock. His performer, Terry Angus, gave Morris glasses so that he could more easily locate himself in the monitors during filming. (He makes an appearance without glasses in "We Love You, Wembley," playing the saxophone.)

Terry Angus originally conceived of Morris as "a cub reporter for the Fraggle news. So in the "Marooned" episode, check his pocket and you'll see that he has a pad in his pocket. It wasn't long that I had dropped the reporter idea and he was just my own background character."

Terry Angus and Karen Prell used to joke that Morris was the (presumably illegitimate) son of the Storyteller Fraggle and Traveling Matt.

References

• Muppet Central post by Terry Angus, 1/28/06
• Muppet Central post by Terry Angus, 11/19/05