Will an average goat beside short curls grow into a cool looking goat next to long shaggy coat? ?
not unless it's a kid from a parent goat with long shaggy curls
Dairy goats that are shown are totally body clipped in the past they go to the show. This makes for a very short coat. As the coat grows out some does procure very shaggy and some don't. The original breed descriptions do have requirements for short coats but they really aren't of any rush here in the US. In England goats are not clipped for showing and hair length is taken into consideration when showing.
I have some Toggenburgs and some Saanens who own a naturally shorter coat and some that are really hairy. The hairy animals tend to enjoy very long hair on their thighs and along their spine.
Answers: It depends on the animal's gender and also on the breed. Bucks and wethers will get hairier as they get elder. Intact bucks often develop long beards, but even our wethers (and my one pygmy doe) have both developed beard and ridges as they've matured. My wethers' sire actually had a full beard that went adjectives the way to the ground - he was a really nice looking buck!
They also tend to get a thicker winter coat this time of year. Pygmies tend to capture hairier than other breeds.
If you have a dairy milker, don't expect her to get shaggy - and you really wouldn't want that, anyway! If you own pygmies, they most likely will get shaggier as they get elder.
Most dairy goats (unless you have an intact buck) will not get these characteristics as they get elder. Dairy goats are typically milkers, and extra hair makes milking and sanitation difficult. We generally even shave udders to help keep things as hygienic as possible.
Edit: Just a fun fact for you. One of the reason an intact buck grows a long beard is that it gives him a nice target to aim at while he's urinating. Rutting bucks stink horribly (I often describe the smell as "hot dead oppossum within the sun". They secrete a musk and urinate all over themselves. Mature bucks are very able at peeing in their own beards. Apparently, it drives the ladies wild.