long sleeve maxi dress silk ASOS DESIGN satin with full skirt and godets in lemon yellow the Iris dress is perfect for formal occasions Tie Front Round Neck Long

By that I mean: has sleeves (at least a short sleeve), either solid or a print that wont date and doesnt look cheap, is at least knee length, and doesnt require shapewear or special undergarments

This dress is under $40, and its very comfortable

& Other Stories Linen Mini Dress RHE Gathered Open-Back Silk-Blend Crepe Maxi Dress Add simple strappy sandals to compliment the dress

Crafted in breathable cotton, this style remains comfortable even on sweltering days

I have had the best experience here

There are no premade specific hungry caterpillar costumes, however you can get adult butterfly wings from Amazon, Amazon AU and Spotlight