Drawstring Cast-On
The Drawstring cast-on is the one I for most of the cat toys I create. It’s designed to allow you to pull the end string after you are finished to close the opening.
Modified Cast On
I originally planned on including the modified version of this cast on here. Once I tried it, I found it trickier to do and it left a larger loop than I liked. And—most importantly—I didn’t see any benefit to it. If you’re interested in it, you can find a video how-to on YouTube.