Gor Koresh is an Abyssin gangster voiced by John Leguizamo, introduced at the opening of The Mandalorian's second season. StarWars.com describes "a low-life gangster on a lawless world" and "a gambler who profits from cruel underground gladiator matches".
He is the first thing the second season shows, and the choice is deliberate: before the series returns to Mandalorian politics it establishes that beskar armour has a resale value and that everyone in the underworld knows it. His attempt to take Din Djarin's suit goes about as well as such attempts usually do.
Catalogue entry. This figure has a verified record here rather than a full write-up — the encyclopedia labels its own depth instead of padding it.