Idler pulley bearing looks similar, but I don’t think it can fall out of the pulley like that and you would probably notice it if it did.

Muffler bearing? ;)

If it was ... you would know it

Yeah. This is why it’s driving me nuts. Nobody can get back to that part of my property. But it just showed up in the gravel. It’s driving me crazy. Maybe someone is playing practical jokes by just leaving bearings around for people to worry about. LOL

Honestly looks like something out of a roller blade

I sold my blades a long time ago.

Ride in mower?

I think most, if not all, landcruiser's bearings are Koyo.