These instructions are only for the tent! Maybe it's just me, but I hate the way that exposed plastic mobiles look. The tent makes for a cute base for an assortment of nursery themes. As you can see, mine is a circus theme (I found the pattern for the elephants here) but this would also pair well with hot air balloons, nautical or whatever you can think of!
Baby mobiles can cost upwards of 40 dollars. I made this entire mobile for less than 10 dollars (not including the cost of the arm, which you can find here.) The entire project took about six hours, but the timeline could vary depending on your sewing experience and patience level.