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Tuesday's Seven Grotesques are secondary villains in Grim Tuesday.
The seven servants of Grim Tuesday were formerly his Dawn, Noon, and Dusk, but he used his Key and copious amounts of Nothing to reshape them to his will. This was so that he could have more servants as the Far Reaches were becoming too big to be policed by his original three. They have less power than the other servants of the Morrow Days, and express a wish to be rid of the form that they have.
Their names were, in order of precedence, Yan, Tan, Tethera, Methera, Pits, Azer, and Sethera (a reference to pre-industrial Scottish sheep-counting methods, which essentially makes their names One, Two, Three, etc.). They had the power to remove memory and kill with their breath. They also, according to the Atlas, had poison spurs on their thumbs.
Dawn, Noon and Dusk