Throughout the production of a series, a lot goes on behind the scenes in regards to planning and design, which often go through multiple stages before resulting in the final version that is seen on screen. Some concepts and ideas can have an effect on the show and characters, and unexpected occurrences during production can also lead to changes and additions to the plans for the show.
Penny Polendina alludes to Pinocchio. This allusion has had the following influences on the character and story:
- The name "Penny" is similar to "Pinocchio". Her last name, Polendina, comes from the derogatory nickname that Pinocchio's creator, Geppetto, was given, due to his yellow wig bearing resemblance to polenta in the original story.
- She is a sentient robot. Pinocchio is a sentient wooden puppet.
- In "A Minor Hiccup", Penny says "I'm not a real girl." This statement is similar to Pinocchio's statements of wanting to be "a real boy".
- She manipulates her swords through the use of very thin wires, similar to how a puppet is controlled with thin strings.
There are no visible differences in appearance between the show and available concept art versions of Penny. One piece of concept art shows that she almost had a pouch strapped to her lower back.