Now this is a happy baby! Wouldn't you be, in such a gorgeous knitted outfit? He's stylin, he's profilin in his gorgeous jumper and hat combo, and on the back we've got an extra happy baby in a gorgeous cabled cardigan. Plus, this pattern goes from 0-4 years, so you can have happy children too!
A lot of DK yarn would work well here but as always I'm going to recommend the King Cole Cherish / Cherished / Cherish Dash DK for these as they're just so perfectly suited to babies and children alike. You'll need 3.25mm, 3.75mm, and 4mm needles, along with buttons and a cable needle for the cable cardigan.