The Gw'oth are alien creatures (singular: Gw'o) first encountered in Larry Niven and Edward M. Lerner's collaborative Fleet of Worlds series of novels (a subset of Niven's Known Space future history).
The Gw'oth resemble starfish and inhabit the ocean under the ice of their home world, the moon Jm'ho. When linked together – using a vestigial talent that few Gw'oth retain – they can form a powerful biological computer. One such instance is named Ol't'ro. Ol't'ro is composed of 16 Gw'oth individuals that link themselves together into a 'meld' or ensemble mind called a Gw'otesht. Ol't'ro is featured prominently throughout the Fleet of Worlds series.
Ol't'ro's ultimate fate is unknown after the Fate of Worlds book in the series. Whether Ol't'ro died in the explosion of planets or somehow escaped is left unanswered. Ol't'ro had just solved the mystery of Type II hyperspatial travel so it is possible but unknown that the Gw'otesht managed to escape in that fashion.