Some have converted a snow blower.
The below is from a well known Van’s RV forum.
Tip: Build Your Own Tug - VAF Forums
”The RV-10 turned out to be a little challenging to push back into the hangar by myself, especially when the ramp has snow and ice. The latest discussion about pushing by the propeller on a CS prop convince me I needed to come up with a tug fast and I did not like the idea of using an electric winch. I found a snow blower at Lowe's.com that would work. 208 cc electric start engine with 4 forward and 2 reverse speeds. It was on sale for only $499.00 with free shipping to the store. 4 bolts removed the auger assembly as a unit and I had some scrap steel from other projects to fabricate the arms and pins. It is built wide enough to allow use with or without wheel fairings. The arms bolt onto the frame with 5/16" bolts. The forward bolts are threaded into a 1" round aluminum rod that fits between the frame sides and provides rigidity to the arms. I had some scrap sheet aluminum that I cut, fit, bent, and painted to finish off the drive belt guard exposed since the auger assembly was removed. I already tested it on snow and it works great getting the RV-10 up the grade and over the concrete 1" lips.”