This crochet pattern for a babies owl cocoon is made in double knitting (dk) yarn and the instructions are for the green cocoon. Cocoons are like baby blankets, but these stop the baby from kicking it of and getting cold feet 3 sizes included Preemie, 0 to 3 months and 3 to 6 months You will require Double Knitting and 3.5mm crochet hook Our patterns are written in UK terminology.