ZOG

Set to 2 different clues across 3 published puzzles, most often “Last king of Albania” — The New York Times, Thursday, 18 March 1999.

3 letters

Every clue on record, most used first

Last king of Albania2 times
The New York Times — Thursday, 18 March 1999
Planet visited by Spaceman Spiff in "Calvin and Hobbes"once
The New York Times — Saturday, 30 May 2009