Inspiration for the costume mechanic was the goblin riders from the silly battle sequence in Jim Henson's Labyrinth.
It took about 4 months from start to finish, with about an extra month for Research & Development. Final estimated cost was around $450.
Primary materials were:
memory foam, for the skin
PVC pipe & plastic canvas, for the skeleton
a whole lot of hot glue & duct tape, to keep everything together
paper mache of a dodgeball for the yoshi head
plastic hangers, screws, bolts & red leggings to create accordian mechanism for toungue
Spray paint for color. Latex paint wouldve been best, but the deadline had to be met
Most importantly, since a fake one just wouldnt do:
the willpower to walk around for 5 months while growing a big handlebar mustache!
Showing off the puppet at Wizard World Comic-Con 2010 in Austin, Tx: