snuggle up, baby cow! these jammies keep baby cozy at night, but don't make him too warm. we purchased the 12-18 month size for our 8 month old, a long and lean baby and they are a snug fit as jammies should be. upon arrival, they felt quite stretchy but lost some give after the first wash. the zipper quality leaves a little to be desired but i'd rather struggle a bit with a sticky zipper than with several snaps as my squirmy worm tries to escape. i'm ready to invest in a second pair...although i think the cow print is my favorite!