This can be worked in any weight yarn; gauge is not important! If you are using a jumbo weight yarn, you will need 2 skeins of each color. Anything lighter and you can get many mushrooms from one skein. Worked in a chunky yarn, the mushroom at my gauge ended up about 6” tall. Worked in a jumbo yarn, it ends up nearly 2 feet tall.

If you want a slouchier cap, stuff less. For a less ‘wobbly’ cap, stuff more.