[Kaderin Triste]

Okay, so it's difficult to get an accurate measurement of Derpy, but for anyone interested in attempting Derpy clothes, his approximate measurements are:
Neck circumference: 6.5 inches
Body circumference: 8 inches
Length (neck to waist): 1.75 inches
Length (waist to top of feet): 2 inches
Wing location (for slit in back of clothing): starts .25 inches below neck, stops .25 inches above waist