Combat rating: -X
In addition, no investigator can have more than 5 Clue tokens at once.
When Yibb-Tstll awakens, X is set to the number of Clue tokens left on the board.
Attack: The first player rolls dice equal to his focus. If he does not roll at least one success, he is devoured. If he rolls two or more successes he is Blessed. It takes twice as many successes as usual to remove each doom token from Yibb-Tstll's doom track.
Doom Track: 11
Yibb-Tstll first appeared in Cement Surroundings (1969), written by Brian Lumley.