In the story of Monster Maker, the Ultragorgon is the creation of special effects wizard Chancey Bellow. The creature appears as an unfinished puppet in Bellow's workshop.
In No Strings Attached: The Inside Story of Jim Henson's Creature Shop, Brian Henson recalls that the Ultragorgon had to be designed and built in just five weeks. Puppet builders assembled the creature in an abandoned church near the Creature Shop, building until they ran out of time, which suited the monster's intentional unfinished look. When the cameras rolled, it took eight puppeteers to bring the Ultragorgon to life: Brian Henson, David Greenaway, Marcus Clarke, Sue Dacre, Michael Bayliss, Christopher Leith, Martin Anthony, and Tony Ashton. Jim Henson revealed at the end of the "Monster Maker" episode that Brian Henson operated the Ultragorgon's head in the Ultragorgon's neck compartment.