Do you mean caruncles? Depending on the strain, they will not come through till they are severall months old. Our females have very small caruncloes all there life. The drakes will be well past the age of starting to fly before you really see any caruncles.
I'm not sure how old my muscovies are because they were given to me in January, but their caruncles didn't start showing up until spring when it warmed, and they had been flying all over the place way before that. it's possible they may have only been a few months old when they came here, because my female didn't start to lay eggs until July--skipping the spring nest all together (unless she just laid them elsewhere and left them to rot).