Oh . . . I see. In that case, unfortunately, there is no option to spawn other full bodies except the Moon in ring presents. What you can do, however, is to spawn in a swarm of particles, select all of them (CTRL + drag mouse), open the object properties menu that should appear on the right side of your screen, and press the button "Convert To Full Bodies." Do be careful that this tends to create a rather severe lag spike, especially if there are a vast number of particles. I recommend limiting particles to several hundred at most before selecting all of them and doing this.