Ruggo the Gnome King
Ruggo the Gnome King is a unique monster added in SLASH'EM.
Ruggo appears on the throne in his special level, located after the (now-misnamed) Mine's End. He generates with the usual inventory for a gnome, but also spawns on top of a random weapon, piece of armor, wand, and two potions. As he is too small to wear most body armor, he will generally leave the armor behind, but will pick up and use the other items.
Ruggo himself is essentially a very high-HP gnome king: he has the same weapon attack, speed, and AC, but a far higher base level. Unlike most gnomes, he resists poison and petrification; his corpse will not convey either resistance, however.
Ruggo is not ordinarily a huge threat, but can be dangerous if the wand he spawns with is an attack wand. Overall, though, he is far less dangerous than the gnolls that frequently spawn alongside him in his throne room.
In earlier versions of SLASH'EM, which were variants of versions of NetHack that did not yet separate races from roles, Ruggo was the gnome quest leader, and his level the home level for the gnome quest. This origin likely explains his resistances, as those are usually given to quest leaders and nemeses.
The Nome King declared, "Cruelty is a thing I can't abide. So,
as slaves must work hard, and the Queen of Ev and her children
were delicate and tender, I transformed them all into articles of
ornament and bric-a-brac and scattered them around the various
rooms of my palace. Instead of being obliged to labor, they
merely decorate my apartments, and I really think I have treated
them with great kindness."
[ Ozma of Oz, by L. Frank Baum ]