This cute little squeezable Kirby Stress ball with optional keychain is fun to make. It is flexible in size but I made it with a 3.5mm hook and worsted weight yarn. It only requires a little bit of each color and a little felt. You will need to provide a rubber squeeze ball (shown in picture) I found some at a good price from Aliexpress. https://www.aliexpress.us/item/3256806079366756.html