Jhonka
From Homestar Runner Wiki
Jhonka was the name Strong Bad created for the writer, who didn't give one, of the e-mail in "impression".
Jhonka shows up in the game Peasant's Quest. The Jhonka is very rich and lives in a cave as shown in Peasant's Quest. He is deathly afraid of the Kerrek and is kind of gullible.
Jhonka vaguely resembles the character Gollum from the Lord of the Rings books and movies. This may be referred to in the Peasant's Quest game, where if you try to "give" the Jhonka something he'll reply with "Don't need nothing from no filthy peasantses!!", echoing the Tolkien character's unique style of speech.
The Easter egg in "impression" provides an interesting description of the Jhonka:
JHONKA The Jhonka are one of many tribes of primitive, troll-like creatures found in the lowlands and throughout lesser dungeons. Their low intelligence makes them quite susceptible to toilet humor and cheap gags such as "Gimme five. Up high. Down low. Too slow." FREQUENCY: Common INTELLIGENCE: Low ARMOR CLASS: +2
This is a reference to Advanced Dungeons & Dragons, in which the entries for monsters followed a similar, albeit more detailed, format.