Look, those damn things (Pluto / Charon, since they’re basically a double bodied system) get closer to the Sun than Neptune, at certain points in their orbit.

There’s dozens of similarly sized objects buzzing around in the same region, and probably thousands of not millions in the Oort cloud.

The only reason “Pluto” were ever called a planet is that they coincidentally happened to be in the wrong place at the wrong time when Tombaugh used Lowell’s miscalculations to look for an hypothetical transneptunian planet (Lowell, at least, had the excuse of having died before Einstein published his theory of relativity, but Tombaugh should have known that Newton wasn’t enough for this kind of thing).