Lightweight merino wool and silk blend pants from European brand Cosilana. Size 50/56 which fits like 0-3 months. Extra length so pants can be cuffed to fit smaller babies. Nice and stretchy with room to grow. Stunning shade of green. Gender-neutral. Amazing basic for sleep or play.
The only flaw to note is a small separation of the fabric on the inside of the waistband (see last photo). In VGUC.