1893 Korea 1 yang, about the same size as the 20 sen.
This bizarre coin's design is based on the design done by a German in 1885, with two dragons and a glowing pearl.
You can see the original design on the 1888 "1 WARN" * coin for example.
The dragons got japified and one of them is clutching the pearl in its talons.
The coins were minted in Korea, but using machines and flans from Japan.
And Yuan Shikai (the guy on the "fat man" dollar) influenced the design,
by complaining about the country's name on the coin.
"Great Korea" was replaced by just "Korea" from this year until after the Sino-Japanese war.
* Beware of counterfeits of Korean silver coins from this period that are larger than this one (1 whan, 5 yang etc.)