Here is a free pattern for you to try. I used a size 4 crochet hook and double knit wool for the red and the grey cardigans. All designs have been slightly adapted, so feel free to play around with different combinations.
Pro tip: Use a fork to make perfect pompoms. I actually tried this and it is works. It's just the part when you tie around the wool, well the wool doesn't go over that tie and it kind of makes it look like a toddler made it
Find out how you and your little builder can make your own LEGO DUPLO reindeer! http://www.lego.com/family/articles/diy-reindeer-stocking-stuffers-and-holiday-decorations-d489bb383b304eba8c391ac41fb806db