It couldn’t be said better than by Mathieu René:

"…For example, for the silly all-encompassing, impossible question: ‘How long does it take to build a puppet?’, They might want to hear any of these, depending on who they are or what they have been exposed to:

* two weeks
* 15 hours of design. 40.56 hours of building.
* about a little bit more than a poof, but less than a millenia.
* It depends on the puppet type, the specifc needs of the project, the budget, the time allowed, the options required, the materials to be sourced, and all the technical needs that need to be met. Really, each puppet is a machine that needs to be re-invented for the purposes of the specific show.

The last answer seems to disapoint a few, and enlighten others."◊

As with many other generic questions (what materials to use when making a puppet, how do puppets work, etc etc), there’s no right answer to the question. As Mathieu points out, the real correct answer is actually the most ambiguous of them all. It disappoints some, who generally have no idea of the complexity involved in making puppets and simply want an easy answer, and enlightens others by revealing a wider and more nuanced aspect of the art form.

In articles here, and in future articles, I talk more about specific puppet types and how long it takes to make them; but honestly, there’s no better reply than "how long is a piece of string?" There is simply no way to summarise it easily in one bite-size sentence. Try watching some of the videos on BlogTV and Youtube that I have made (or others have made) and you’ll start to realise just how lengthy some processes are, and how short other processes can be, and how many different techniques there are. Just as there are conservatively 63 000 000 000 000 000 000 000 000 000 000 (see my calculations here) possible puppet characters out there, there are just as many, if not more, ways to build a puppet. This doesn’t include of course, the time spent remaking, repairing, or simply improving the puppet for future performances. Making a truly incalculable number of minutes and hours that can be spent on creating a single puppet. 

◊ The quote is taken from Puptcrit Digest, Vol 66, Issue 11: Sharing info or trade secrets?

… This post AKA how long does it take to build a custom puppet