Author of the MULE SKINNERS BIBLE
The reason I call this the thief knot is because it is so quick to untie. I use this knot to tie my mules, and when you get used to it, it is a very easy knot to untie. Another thing is that it is handy, as all you have to do is yank on the tail and it releases. This is exceptionally handy for leading a pack string in that you can just ride by and grab the end of the rope (as shown above) and ride off, and you have the lead mule secured before you ever release him.
Figure 1 shows how you start the tie, then in Figure 2 you have taken your right hand and shoved the loop through the loop you were holding with your left hand. Now you have the tie completed.
Figure 3 shows the completion, and your right hand is holding the rope coming from the mule. Now, if you are going to leave your mule tied for a while you should half-hitch the ear of the tie so the mule can’t grab the end with his teeth and release himself, as shown in Figure 4.
There are other ways to use this knot, for instance you would like to have someone hold a green mule while you get on, and you are by yourself, just tie one end of the rope to the hitching rail and loop the rope through the halter and make the same type of tie knot. After you get on just take the end of the rope and pull on it and release the mule after you have mounted.
Another way I have used it is if I have a green team and I am by myself. I will have hitched the team tied to the hitching rail so as to have them secured while I am getting in the wagon after I have untied them from the hitching rail. I will tie the left mule with the same procedure as I did with the mule I wanted held when mounting. In this case I needed a longer rope to come back to the wagon, so I could release the team after I got in the wagon. In this case I generally had a short rope tied between the bits, so as to keep the right hand mule tied to the left mule until I released them. Of course, when you release them you just let your rope lay. When I release the team I swing them to the right to take off.
You will find this knot very handy after you get the hang of it, so play with it until you get it right.
Hope you enjoy these tricks of the trade.