My 3.5 year old son is slim and looks skinny in most pants. It's a really slim fit and very good quality. So far this brand is great for its build.
Waterproof Cozy-Dry Rain/Snow Pants for π§ Kids by JAN & JUL, with Fleece Lining
64 Review
π Boys' Outdoor Climbing Convertible Trousers - Waterproof | Clothing
47 Review
Arctix Youth Pants Reinforced: Large Boys' Clothing for Active Adventures
46 Review
π Bold Pack Sleeve Active Hoodie Sweatshirt Set for Boys' Clothing - Stylish and Comfortable!
47 Review