What is the Oh-My-God particle?

It was the highest energy cosmic particle ever observed, several dozen million times more energetic than the most energetic particle ever produced on Earth (in the Large Hadron Collider) and significantly higher than was predicted by the prevailing theories. It concentrated the energy of a well-pitched fastball into the space of one proton.

https://en.wikipedia.org/wiki/Oh-My-God_particle

I'd love to use my "own words" as stipulated but fear that my vocabulary us too limited, So...

As of 2023 [the Oh-My-God particle] is the highest-energy cosmic ray ever observed.[4] Its energy was estimated as (3.2±0.9)×1020 eV (320 million TeV). The particle's energy was unexpected and called into question prevailing theories about the origin and propagation of cosmic rays.

https://en.wikipedia.org/wiki/Oh-My-God_particle

See also https://futurism.com/what-is-the-oh-my-god-particle