Could it be a frogcritter?
I’d need to hear it to see if it is anything in my experience list, but we have some strange sounding frog things around here. And yes, mockers can and will sound like many strange and unusual things so don’t count one of those out just because he was wearing camo that morning.. ;-)
Wow, I hadn’t even considered frogcritters! We usually have beaucoodles of them around here, but I haven’t been outdoors much, and it has been rather cold recently. I’m pretty certain that a mocker wouldn’t have been schlepping around in the mud puddle. I knew you’d nail it! Thanks a bunch! Regards to all....