A Yeti of Your Own

Say! You know what?! You're an engineer too! So, since you helped me teach my friends a lesson, I'm going to teach you how to make your very own mechanical yeti! Now the fun can go on forever and ever, and you can scare whoever you want! Provided that you can scare up the components to make it that is.

What do you say, friend? Do you want to learn the secret to making a mechanical yeti?