Because HELLO, so cozy!
I learned something very important making these. That if a pattern is well designed (and this mother better be- you may recall 2011 Battle of the Frontal Butt), that it will be great on a few different baby body types. I originally created this 12-18 month pants pattern for Phinny when she was shooting up and slimming down. I haven't changed it here. (Yes, my not-yet-5 month old son wears 12-18). I just made sure the waistband was ample for chubs, and let them be long so he can grow into them. I think that even with the extra length they look right. I am pleased.