Flashing Swords 1(1973)
(The first book in the Flashing Swords series)
An anthology of stories edited by Lin Carter
The Sadness of the Executioner - a Fafhrd and the Gray Mouser story by Fritz Leiber; Morreion - a Tale of the Dying Earth by Jack Vance; The Merman's Children - Viking fantasy by Poul Anderson; and The Higher Heresies of Oolimar - Almaric the Mangod by Lin Carter.
Used availability for Lin Carter's Flashing Swords 1