I made this Nacho Libre costume for my 8-year-old son. We started with his white baseball pants worn with his bright blue underwear on top of them. We used a black frizzy wig from Wal-Mart. Drew on the mustache with eyeliner pencil. The cape is made from a red pillowcase that was just pinned onto the back of one of my bright red polyester shirts.
To make the boots, I cut the arms off of an old red sweatshirt and then used some black shoestrings to criss-cross up to make it look like wrestling boots.
His favorite line for the evening was: “Sometimes grown men wear stretchy pants in their rooms at night.” Everyone knew exactly who he was and the costume was a hit.
The whole Jack Black as Nacho Libre costume cost less than $10 because the only thing we bought was the wig. Everything else came from around the house. It took us about 30 minutes to assemble.