Great drawings. I would like to here more about eyelash yarn myself-Steve

I like that drawing, and more the idea to becoming a puppet!

You've made a beautiful start with the drawing.  The most challenging part is building the body so that it both light and sturdy.  I've built some puppets that had a rounder body like the one your puppet will have and have found that building the body out of 1/2 polyfoam reinforced with wires has worked well.  The advantage of the wire is that if the puppet is knocked out of shape it can be returned to the shape you want.

Thanks everyone for all your advice! I'm going to start working on the puppet in around 4-6 weeks. The reason for this big gap is so I can save up money to go buy materials and also, I need to get my exams for school out of the way, heheh. So, hopefully, I can keep you all updated on the progress of the monster! I'll try my best to use the cage ideas, they sounds like a fairly solid idea to use.