I'll ask you to select one when I draw for you.
I would default certain species to certain body types, but you can choose a different one if you like.

A. Endomorph; Tends to be stockier and puts on weight more easily. Shorter arms and legs, and a larger torso.
Suits larger/slower characters and 'heavy hitters'.
e.g. bears.

B. Mesomorph; Between the other two. Puts on muscle more easily.
Suits all-round characters
e.g. wolves, dogs.

C. Ectomorph; Tends to be lankier and looses weight and muscle easily. Long arms and legs, short torso.
Suits faster/more agile characters.
e.g. Cats, foxes.