It took me about a year to complete a full size working Karasu puppet (right down to the spring out blades) but it was worth it.

Pros: the most comfortable costume i've ever worn, the puppet could be folded to fit into the wrap on my back for easy transport

Cons: Karasu was slightly heavier than i anticipated (about like carrying a 40lb backpack)...and the elevators at ohayocon are SO SLOW i had to use the stairs a lot...argh