Original publication, Galaxy Science Fiction, December 1965
Also released in December 1965, Paingod and Other Delusions included '"Repent, Harlequin!" Said the Ticktockman'
The Voice from the Edge, Vol. 1: I Have No Mouth and I Must Scream by Harlan Ellison, Read by Harlan Ellison, Fantastic Audio, 2002
The back!