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This article relates to the Duncan Idaho ghola. For the Harkonnen Mentat in Dune 2000, see Hayt De Vries.

Hayt was the first ghola of Duncan Idaho which was produced by the Bene Gesserit in a plot to kill Paul Atreides. However, the ghola regains the original Duncan Idaho's memories. He later marries Alia Atreides. He is later killed by Stilgar.