Nudibranch means “naked lung.” The flower-like structure on a sea slug’s back is actually its exposed gills. Nudibranchs come in many colors and patterns. With this digital crochet pattern, you can make your own! Most of this pattern is worked in the round. Some sewing is required. The pattern uses US terminology. When made with size 4/worsted weight yarn and a size F/3.75mm crochet hook, the finished piece should be about 8 inches long and 3 inches tall.