I'd venture to say the starfish is the easiest royal icing animal you can possibly pipe; it consists of nothing more than stiff consistency royal icing and round tips. I made them in three different sizes using #'s 8, 10 and 12. The tiny dots are piped with a round #2. Pipe the starfish on a large piece of parchment paper; I cut these to about 4".
Start the first leg by piping a ball, then elongating it in a random sort of fashion. Hold the tip at a 45 degree angle in the center of the parchment, squeeze until a ball forms, then move the tip along as you see fit. End some of the legs with an upturned tip, like this. You can perfect the tips with your fingertips after touching them to a dusting pouch filled with a 50/50 mix of cornstarch and powdered sugar.
Pipe little dots all over the starfish, if you like. I used a #2 tip, and made the dots larger in the center, and smaller as I piped dots down the legs.