The book doesn't specify if the monster was created by one man or several or how he was brought to life. I think we can safely guess that the monster was brought to life using electricity because it has such an influence on Victor. SPOILER ALERT. I would also say that is safe to say that the monster was probably created using more than one man because later on Victor tears apart/destroys the monster's companion before he completes her creation. These are just my thoughts and if anyone has anything else they would like to add please comment
In 1792, while visiting friends in France, Wollstonecraft met Captain Gilbert Imlay, an American timber merchant and adventurer. Taken by him, she soon became pregnant. They named their daughter Fanny, after Mary’s best friend. While nursing her firstborn, Wollstonecraft wrote a conservative critique of the French Revolution in An Historical and Moral View of the Origin and Progress of the French Revolution . She also wrote a deeply personal travel narrative, Letters Written During a Short Residence in Sweden, Norway and Denmark , which became her most popular book in the 1790s. After their travels to Scandinavia, Imlay left her.